SA Roofing September 2015 | Issue: 73

WWW.TRADEMAX.CO.ZA

SEPTEMBER 2015 ISSUE: 73

SA R36 EACH INCL. / R360 PER ANNUM INCL.

SEPTEMBER 2015

ISSUE: 73

EDITOR’S COMMENTS...................................................................................................... 2 CONTRIBUTORS................................................................................................................. 6 ENERGY EFFICIENCY REGULATIONS..................................................................10-11 ASPHALT ROOF SHINGLES..................................................................................... 13-14 COVER STORY............................................................................................................. 16-18 BRACING....................................................................................................................... 20-24 LGS ROOF SYSTEM.....................................................................................................26-28 AMPA COMPANY NEWS................................................................................................ 30 OCCUPATIONAL HEALTH AND SAFETY..........................................................34-35 ROOFING MATTERS: FASTENERS....................................................................... 36-40 STEEL AWARDS 2015 WINNERS........................................................................... 42-57 MARKETING COMMUNICATION........................................................................58-59 THATCH ROOFING.................................................................................................. 60-63 STEEL INDUSTRY.............................................................................................................. 64

Trademax Publications SA Roofing Tel: 0861 SA ROOF Tel: 0861 727 663 Fax: 0866 991 346 Email: info@trademax.co.za www.trademax.co.za Postnet Suite 241 Private Bag X103 N1 City 7463

PUBLISHER: Billy Perrin 082 266 6976 billy@trademax.co.za EDITOR: Tracy Swain editor@trademax.co.za ADVERTISING: Jacqui Marsh jacqui@trademax.co.za LAYOUT & DESIGN: Craig Patterson craig@trademax.co.za SUBSCRIPTIONS: Belinda Thwesha belinda@trademax.co.za

16

DISCLAIMER The views expressed herein are not necessarily those of Trademax Publications. Although we have done our best to ensure the accuracy of our content, neither Trademax Publications nor SA Roofing magazine will be held liable for any views expressed or information disseminated, in editorial content or advertisements, in this issue.

13 SEPTEMBER 2015

34

42

EDITOR’S COMMENTS

Steel a glance!

It’s that time of the year when we sit up and take special note of steel – celebrating the excellence of steel construction, and more specifically, demonstrating its vast potential in terms of innovation and sustainability.

E

ach year, the SAISC Steel Awards attract outstanding entries across a wide range of projects, and this year, judging from the winners, it was nothing short of spectacular. From a SKA radio antenna positioner that radiates excellence delivering images of the Centaurus A galaxy – some 13 million light years away, to a meticulously designed canopy walkway. Of course, the entries in the Light Steel Frame Building (LSFB) category cannot go unmentioned. This year’s Steel Awards also saw stellar entries from LSFB that suitably showcase the industry’s innovation capabilities and design efficiencies.

It was humbling to look over such exceptional steel projects, even whilst the industry is experiencing some challenges. We are hopeful that, with the appropriate dialogue between key stakeholders, these challenges can be overcome. Enjoy the special ‘steel spread’ starting on page 42.

2

Aside from the dazzling Steel Awards 2015 winners, and with current legislation in mind, in this issue we also take a look at the new Regulation 18: Rope Access Work in terms of the Construction Regulations, 2014, of the Occupational Health and Safety Act, 1993. For guidelines relating to this regulation, read the article on page 34.

Moreover, you can also learn more about fastening systems, bracing, thatch and asphalt roofing on the pages of this edition, making for a well-rounded read.

As always, feel free to drop me a line, but before I sign off, I want to extend a hearty congratulations to all the winners of the Steel Awards 2015. Keep flying the flag of architectural excellence!

Until next time, Tracy

SEPTEMBER 2015

Built over years, perfected with time.

JCP Roofing is a family business that came into existence through JCP STEEL, a company that has been serving the steel industry with flat steel products for over 22 years, with a reputation for excellent service, uncompromising quality and impressive lead times.

Expanding our portfolio to supply IBR and corrugated roofing sheets to the same level of service our customers grew accustomed to over the years, has been our vision and dream. Take the time to call us on 011 814 1898 and we will help you perfect your project Products: IBR • Corrugated • Polycarbonate Sheeting • Bullnosing/Cranking • Flat Sheets • Screws & Fasteners Tel: +27 11 814 1898 | Fax: +27 11 814 2166 Email: info@jcproofing.co.za | Web: www.jcproofing.co.za

BOOK NOW!

9-11 EXPLORE JUNE NEW BUSINESS

OPPORTUNITIES 2016 AT AFRICA’S ONLY TIMBER MACHINERY, TOOLING, MATERIALS & FITTINGS EXHIBITION Furniture & Kitchen production | Forestry & Sawmilling | Wood Materials, Machinery & Veneers Tools, Loggers & mobile Saws | Timber Construction and supply | Industry Surface & Treatment Technologies Many more Timber related products, machinery and services.

Gallagher Convention Centre | Midrand | South Africa info@woodexforafrica.com | +27 (0) 21 856 4334 www.woodexforafrica.com

CONTRIBUTORS

Contributors REITZE HYLKEMA

Reitze Hylkema has been the managing director of Kare Industrial Suppliers for the past 20 years and has been involved in the marketing of fastening systems for over 30 years. He is actively involved with the Corrosion Institute of Southern Africa and the Southern African Light Steel Frame Building Association and is also a participating member of various technical committees at the SABS relating to roofing, fasteners and corrosion. He feels strongly about “fit-for-use” quality in all construction materials, especially in roofing, and for him, educating the market is imperative. His hobbies include scuba diving and CrossFit training.

GARETH GRIFFITHS

Gareth Griffiths is the owner of ENERGY|MC, an independent content creation and media service in Cape Town. A qualified physical scientist and materials engineer at post-graduate level, he offers unique skills compared to other writers. His working career of some 25 years spans experience in media, technical writing, magazine editing, sales and marketing. Gareth is available to undertake freelance writing, social media and also to supply professional photographic content.

JOHAN LOUW

Johan Louw is the director and senior consultant of Johan Louw & Associates, specializing in occupational health and safety solutions for training, auditing and consulting. In 1983 Johan qualified as a mechanical engineer from the University of Pretoria. His early career began at Atomic Energy Corporation as an engineer-in-training. He then moved to Du Toit, Lindeque and Van Den Berg, a consulting engineering firm, in the capacity of mechanical design engineer. From there he moved on and joined Armscor as a Systems Engineer. During this period he furthered his studies at the Loughborough University of Technology in the United Kingdom, where he obtained a Master’s Degree in Ergonomics in 1989. Johan has been involved in establishing numerous occupational health and safety ventures, and has been affiliated with significant role players in establishing a Health and Safety Standard in South Africa.

ERROL HOBDEN

After having worked as an engineer mainly in reinforced concrete systems, Errol Hobden started out in the prefabricated roof truss industry with International Truss Systems in 1994, and after a year he was promoted to manager of technical services. In 1996, he was offered a position with a company called TeeLok in the USA, also metal nail plate manufacturers and engineering system software suppliers, after which he worked for a number of truss manufacturers in the USA, gaining a vast amount of operational experience. In 2012 he returned to South Africa and rejoined International Truss Systems.

Waterproofing problems?

Rubber It can help!

Rubber It’s liquid spray-on rubber can solve all your waterproofing problems.

What they offer:

WESTERN CAPE & EASTERN CAPE www.aspectwp.co.za

Roof waterproofing – concrete, IBR, corrugated and tiled Waterproofing of dams, water reservoirs, bridges and foundations A written 10-year replacement guarantee on the product and labour SABS tested 0% VOC and HAPS, environmentally friendly Ebonite 101

You name it, they do it! No job too big or small!

Rubber It has a branch in KZN and is looking for more agents.

• Reliable • Quality • Efficient • Service

Contact: Dudley Visser

21 YEARS ON AND

STILL GOING STRONG

(t) 012 567 4625 (c) 072 794 8534 (e) d.visser@live.co.za

www.facebook.com/rubberitliquidrubber

(021) 460 0453

(041) 360 0094

ENERGY EFFICIENCY LEGISLATION FOR NEW BUILDINGS (NBR-XA) The National Building Regulation (NBR) was updated in November 2011 to include Part X, which addresses environmental sustainability and Part XA which establishes requirements for energy efficiency in new buildings and renovations (which require plans). The application of this new legislation is good news for the environment and will help you save electricity.

FEEL THE REAL DIFFERENCE WITH INSULATION THAT MEETS THE REQUIREMENTS Buildings typically account for 40% of all energy consumed in countries and by insulating with Glasswool it is possible to significantly improve the energy efficiency and comfort of buildings. Isover`s insulation can save 100 times the energy consumed and CO2 emitted in their manufacture, transport and disposal.

Glasswool is made from a combination of naturally occurring silica sand, fluxing agents and up to 80% recycled glass. Glasswool has Zero Ozone Depleting Potential (ODP) and no CFC`s or HCFC`s are produced in the production process. Glasswool can be compressed by a factor of up to 5 which saves on storage and reduces transport costs.

CEILING INSULATION A typical un-insulated home loses and gains up to 35% of its energy through the ceiling and this can be dramatically reduced by installing insulation of the correct thickness.

Think Pink Aerolite is Isover’s thermal and acoustic ceiling insulation solution that reduces the amount of energy required to maintain a comfortable living environment, offering a payback in less than 2 years with continued savings thereafter.

Isover Insulation 130 is a non-combustible Glasswool blanket that has been specifically developed to meet the Department of Human Settlements ceiling insulation requirements for 40m2 housing developments became effective in April 2014.

Our insulation is environmentally friendly, non-combustible, offers excellent sound absorption properties and is easy to install in your home.

Feel the real difference with Aerolite or Isover Insulation keeping you warm in winter and cool in summer.

For more information log onto www.isover.co.za or download our Isover SA app in the app stores.

Tel: 0860 ISOVER (476837) Fax:

M

R E S I S TA N C E

TH

ER

AL

VA L

UE

Isover Insulation 130

086 673 1088 www.isover.co.za

E N E RGY E F F I C I E N C Y R EG U L ATI O N S

Energy Efficiency – the power of action In South Africa, electricity prices have increased by more than 200% since 2009. The country has a critical shortage of electricity supply, and this amongst other things, has led to critical regulations and standards being implemented to reduce our energy consumption.

SANS 10400-XA: 2011 ED.1 SANS 10400-XA: 2011 Ed.1 Energy Usage in Buildings is in the process of being revised. It is common practice to review energy standards every five years and update them to more stringent levels to achieve energy savings. The Energy Efficiency Regulations were promulgated in November 2011, yet approximately only 5% of all new buildings comply with these regulations. The enforcement of the regulations has not been consistently applied across the country. Cities such as Cape Town and Durban are currently leading the way with regards to designing and creating buildings that comply with energy efficiency regulations. According to the National Building Regulations, it is the owner of the building that is ultimately responsible for the energy performance of the building.

“...only 5% of all new buildings comply with these regulations.”

BUILDINGS AND ENERGY CONSUMPTION With buildings accounting for nearly 40% of global energy consumption, the building sector should play a key role in effective energy savings. Existing buildings provide an enormous opportunity to reduce their energy intensities, whilst simultaneously driving improvements in public health, labour productivity and job creation.

In many existing buildings, the roof and ceiling are often not insulated properly or not insulated at all. Many people fail to realize that a building system can have a huge impact on a building’s energy efficiency. The building envelope plays a critical role, as it forms the barrier between a building’s interior and exterior environments. A well-insulated and/or welldesigned building will provide year-round comfort, cutting cooling and heating costs and reducing greenhouse emissions.

“...buildings accounting for nearly 40% of global energy consumption...”

NEW REGULATIONS IN THE FUTURE SANS 1544 Energy Performance Certificates for Buildings was published in December 2014. It stipulates the methodology for calculating energy performance in existing buildings. Initially, it is a voluntary standard, but it is envisaged that it will soon become a mandatory standard. It is applicable to all publicallyowned buildings.

ADVICE TO ARCHITECTS The design of the building is the responsibility of the architect, and hopefully their Professional Indemnity (PI) insurance will be sufficient to cover any actions taken by the building owner should the design not perform as required.

We should concentrate on existing building stock by retrofitting insulation – i.e. adding insulation on top of the ceilings.

“SPEAK TO US – We provide the TiPS you never knew you needed”

TEL: 0861 000 334 | MOBILE: 082 305 8559

10

SEPTEMBER 2015

These changes in the industry will force industry professionals to specify highquality products and materials. This will also ensure that projects are seen through from specification to the installation. Too often building contractors still change products specified by the architect to something cheaper, not realizing that this could compromise the energy efficiency design or, just as importantly, the fire safety aspect of the building.

It is imperative that only products and systems that were tested, and proven to be in compliance with the National Building Regulations and Standards, be selected.

This includes properties such as fire testing, durability and thermal efficiency, ensuring that the products used in buildings are correct and safe.

IMPLICATIONS OF NON-COMPLIANCE It is an offence to erect a building without plan approval. In terms of Regulations A4(6), any person who provides false or misleading information in a notification in terms of the sub-regulation shall be guilty of an offence, and such notification will be considered to be null and void. Where any person provides any such misleading information or false certificate required in terms of Regulation A19, or which he or she knows to be incomplete or false, such person shall be guilty of an offence.

Guilty offenders are liable for a fine or up to 12 months imprisonment.

Acknowledgement: TIPSASA (Thermal Insulation Products and Systems Association SA).

For more information, contact TIPSASA on 0861 000 334 or 082 305 8559, or email dschnetler@mweb.co.za.

SEPTEMBER 2015

Why is Africa turning to the roofing shingle system?

– Because it’s worth it

TruDefinition® Duration® Shingles provide greater contrast and dimension to any roof.

This range offers the patented SureNail® Technology with triple layer protection and excellent adhesive power.

• Wind resistant • Minimal maintenance • High UV resistance • Extremely lightweight • Thermal efficiency

THE PINK PANTHERTM & © MGM. All Rights Reserved

Like us!

Follow us!

Tel: (011) 903 7080/1/2/3/4 | Fax: 086 634 7850 | E-mail: tammy@gissa.co.za or learn more on www.gissa.co.za

A S PH A LT ROO F S H I N G L E S

Sustainable shingle roofing system gaining traction in St. Francis Bay A gracious canal house in St. Francis Bay gets stylishly covered with the Owens Corning Shingle Roofing System.

After: Homestead with roofing shingles covering

CHOICE SELECTION With so many roofing options available to property owners today, it’s no surprise that homeowners and landlords are opting for various roofing systems in equal measure. Property owners, Mr and Mrs Tuberville, decided it was time to give their gracious canal home in St. Francis Bay a new look and accordingly selected the Owens Corning Shingle Roofing System to replace their previous thatch roof.

NEW SYSTEM WITH A PROUD HISTORY Though relatively new in South Africa, this roofing system has been used in the USA since the 1800s.

SEPTEMBER 2015

The roofing system is distributed locally and in various parts of Africa by Global Innovative Building Systems for Owens Corning – the leading manufacturers of this unique roofing system in North America.

With its many benefits, thatch has been the iconic roof covering in St. Francis Bay’s architecture for many years, but according to renowned architect Mike Morrisson, asphalt roof shingles are being accepted as an alternative roof covering option in this area. Over the past few years, there have been many successful shingle roofing installations in St. Francis Bay, specifically where companies such as W&D Roofing have been able to convert thatch roofs to shingles without removing the existing structure.

13

A S PH A LT ROO F S H I N G L E S

Before: Homestead with thatch roof covering This is of particular importance as the roofer is able to maintain the original roof architecture, thereby preserving the style of the homestead. This also reduces the cost of converting a roof as new trusses are not required.

The profile of the roofing shingle affords installers and designers flexibility in their being able to cover various roof shapes and geometries that could pose a challenge for other roofing materials. The low profile and interlocking design ensures that the roof is resistant to wind and water ingress – offering a completely protected roof covering with an added security element for any building.

UNIQUELY BENEFICIAL • Lightweight – weighing 22kg/m² • Asphalt shingle has rigorously been tested for fire safety (UL A1 Fire Rating) • Asphalt shingle has passed the ASTM E 108 and SABS 'burning brands’ test • Low maintenance and easy installation – therefore cost-saving on repairs

For more information, visit www.gissa.co.za.

Owens Corning Shingle Roofing System

14

SEPTEMBER 2015

Leaders in Roof Truss Technology Fabricators Sheeters Erectors Tilers

COV E R S TO RY

D&D Roof Insulations –

keeping the industrial, commercial, retail and residential building insulation sectors covered for 15 years

OUR STORY Established in 1999 and headquartered in Pretoria, D&D Roof Insulations specializes in the supply of a diverse range of roof insulation materials for all industrial, commercial, retail or residential building structures. With over 15 years’ experience, this industry-recognized thermal insulation specialist is ideally poised to deliver the right product according to every client’s specification.

16

With its broad offering, the company can, and has been delivering superior service and competitive pricing. Clients derive first-hand benefits from its specialist technical expertise in aspects such as thermal efficiency data, with the team drawing on many years of collective experience in the roof insulation industry. Although the business is headquartered in Pretoria, its products are supplied across South Africa and are exported to some African countries as well.

SEPTEMBER 2015

COV E R S TO RY

UNRIVALLED CLIENT SERVICE D&D Roof Insulations partners with each of its clients to provide critical guidance on construction projects – from the planning phase through to completion. Construction professionals can expect to gain pertinent thermal design and ventilation knowledge as it relates to their custom projects.

This ensures that the contractors, roofing sub-contractors, construction team and/or developer are all fully satisfied that the best roof insulation has been applied to meet specific project needs.

The team at D&D Roof Insulations can also offer recommendation in respect of complementing accessories across the insulation product range. Aesthetics play an important role in construction projects, and the highlyknowledgeable team takes pride in selecting the ideal thermally-efficient roof insulation materials that also hold visual appeal.

The business firmly upholds professionalism, and appointing approved roofing contractors ensures installations are carried out correctly from the outset.

STARLITE ® - THE PREMIER BRAND OF INSULATION As a proudly South African brand, Starlite ® has an unblemished, 11-year track record of being successfully applied in commercial and industrial roof, as well as side-cladding projects. With a thermal conductivity (K-value) of 0,039W/m.K and a noise reduction of coefficient (NRC-value) of 0,65 at a 50mm thickness, it is a highly effective thermal and acoustic insulating material. Not only fire rated, but also considered to be one of the most affordable and eco-friendly insulating products available, the brand also boasts one of the best performanceto-cost ratios in the market. It’s no surprise that so many bluechip brands have opted to use the Starlite ® technology in their construction projects.

D&D Roof Insulations continually seeks to raise the benchmark in client service, and providing details of approved roofing contractors is another way the company delivers on this.

SEPTEMBER 2015

17

COV E R S TO RY MANUFACTURING PROCESS

TIPSASA

Comprising of a lightweight fibreglass insulating blanket combined with a scrim reinforced aluminium foil, Starlite ® is easily installed in conjunction with cladding, offering the added advantage of definitive visual appeal. For over-purlin applications, it is also available in white foil laminate facing.

Produced from molten glass, the fibreglass also includes natural raw materials such as limestone, sand, soda ash and approximately 80% post-consumer recycled glass.

D&D Roofing Insulations is committed to evolving with market changes and divergent opportunities and challenges, and is proud of its founding affiliation with the newly-formed Thermal Insulation Products and Systems Association SA (TIPSASA).

The Association focuses on the thermal insulation industry specifically as it relates to energy-efficiency systems and products. Its vision hemmed in energy-focused innovation is strategically aligned with D&D Roofing Insulations’ pursuit of product evolution to better suit its clients’ markets.

The glass is melted down in an enclosed furnace that uses a 100% electric melting process. By utilizing this method, no particulate emissions and exhaust gas fumes are present, thereby ensuring a pollution-free production process that is in accordance with ISO 9001:2008.

Once melted, the glass is then spun into fibres and bound together with an inert binder and cured with heat to produce a resilient, non-toxic blanket. During the manufacturing process, Starlite ® does not produce blowing agents, has zero Ozone Depleting Potential (ODP) and is CFC-free. Using a specially-produced, water-based adhesive, the aluminium foil or white laminate (dependent on the client requirement) is glued to the fibreglass. This technique also ensures that no solvent fumes are emitted.

FOR MORE INFORMATION, CONTACT D&D ROOF INSULATIONS: (t) 012 800 3606 (e) info@roofinsulation.co.za (w) www.roofinsulation.co.za

Starlite ® is exclusively supplied by D&D Roof Insulations – an industry-recognized thermal insulation specialist and a member of the Green Building Council of South Africa (GBCSA) and the Thermal Insulation Products and Systems Association SA (TIPSASA).

18

SEPTEMBER 2015

B R AC I N G

Bracing, bracing, bracing Bracing is one of the most overlooked aspects of roofing. With this in mind, SA Roofing takes an in-depth look at this important facet of the roof system – with the help of expert engineer, Errol Hobden of International Truss Systems.

I

n the real estate world the estate agents have a mantra, “Location, location, location.” We have all certainly heard this phrase many times. You may wonder why the word location is repeated three times. The reason is to emphasize the importance of the location of the property when purchasing real estate. If you purchase a property in a good location, the property is most likely to increase in value over time, giving you a good return on your investment. Location is the number one rule in real estate, and it’s often the most overlooked rule.

This code has some ‘deemed to satisfy’ truss designs that one can use to construct nail and bolted trusses with lapped joints.

The truss types are limited to a maximum truss span of 8m and a minimum pitch of 15 degrees. The roof type is limited to a gable-to-gable roof meaning that the roof cannot contain any hips. The minimum timber size that can be used is also limited to 38mm x 114mm. The reader is advised to refer to the code for further limitations that are applicable to these deemed to satisfy truss types.

In the roof truss industry, this phrase can be translated as, “Bracing, bracing, bracing.” Bracing is one of the most important, integral parts of a roof structure, and it is also one of the most overlooked parts. Many contractors don’t realize that most roof failures are a result of inadequate bracing. A roof structure can be perfectly designed and manufactured, but if it is not correctly erected and braced, you will end up with an unsafe roof that will in all likelihood wind up costing you a considerable sum of money in the future.

At present, both SANS 10243 and SANS 10400-L codes are in the process of being revised.

SANS 10243:2004 is the current South African National Standard that covers the manufacture and erection of timber trusses. This code has been designed to act as a guide on the manufacture, erection and bracing of timber roof trusses.

SANS 10400-L: 2011 - The application of the National Building Regulations - Part L: Roofs. This code covers mainly site-made trusses with lapped members.

20

International Truss Systems (Pty) Ltd (ITS) and some of the other metal nail plate system suppliers, in conjunction with The Institute for Timber Construction South African (ITCSA), have over the years developed numerous guidelines that explain the correct procedures in erecting and bracing a timber roof structure. All these details have been published by the ITC-SA and are contained in two publications: Roof Erector’s Handbook Volume 1 and Roof Erector’s Handbook Volume 2.

ITS as well as the other metal nail plate system suppliers also have their own bracing manuals that contain some of the details found in the ITC-SA Roof Erectors’ Handbooks, as well as details pertaining specifically to their own range of proprietary truss hardware.

SEPTEMBER 2015

Roof Erector’s Handbook Volume 1 is designed as a pocket guide that can be carried in your shirt pocket for quick reference. It contains some of the basic “do’s and don’ts” in roof erection and bracing.

Roof Erector’s Handbook Volume 2 is a more concise publication that contains all of the most common bracing requirements needed for the majority of the roof type structures found in South Africa.

Both Volumes 1 and 2 are deemed to satisfy bracing rules that will work for most roof type structures found in South Africa.

In the case of very complicated or very large span roofs, it is advisable to have an accredited Timber Engineer or the System Engineer review the bracing requirements for the roof structure before any of the trusses are manufactured. All roof structures for public buildings are required to be reviewed and checked by an accredited Timber Engineer or the System engineer.

The importance of bracing in a roof system cannot be emphasized enough. Bracing is a crucial, integral part of a roof system that is quite often not treated as such. Designers and erectors are often both at fault here.

Designers must pay more attention when preparing the truss erection drawings. Their drawings are to clearly communicate their intention of what is needed to correctly erect and brace the roof. All site erection drawing packages/job package should contain a truss layout drawing, bracing details and the truss profile drawings. Each truss layout drawing must identify and show the positions of each truss, the position of each braced bay, and the position and type of each hanger or cleat needed in the roof. The bracing details can also be included on the truss layout drawing if possible; otherwise a separate drawing can be prepared for all the applicable bracing details for the roof. Quite often the truss profile drawings are excluded from the site erection drawing package. This is not good practice as it makes it harder for the erector to be able to clearly identify which webs need to be braced or the correct positioning of the bottom chord runners. Each truss profile drawing must clearly show the position of the required web and bottom chord runners.

Roof erectors should also pay more attention to the drawings contained in the site erection drawing package/job package. It is advisable for them to take some time and study the drawings to make sure they completely understand what is required in erecting and bracing the roof. If they have any questions they should contact the truss designer for explanation.

B R AC I N G

Erectors should be aware that only the proprietary hardware of the specific system whose engineering software was used to design the roof trusses may be used in the roof system. The reason for this is that the engineering software programmes use the tested design values of their specific, associated hardware in the design of the roof. Using hardware from an unknown source could relieve the metal nail plate system supplier from all responsibility for the roof.

SOME OF THE MOST FREQUENTLY ASKED QUESTIONS ABOUT BRACING: DOES THE BOTTOM CHORD OF A TILED ROOF NEED TO BE BRACED? One of the main purposes of bracing, and in this case lateral bracing, is to reduce the effective length of compression members. Sheeted roofs are more prone to the effects of wind loads than tiled roofs, and during high-speed wind storms the trusses in the sheeted roof could experience a process called reversal of stresses. What happens is that the trusses want to lift off the building, and in this process the stresses in the bottom chords of the trusses change from being in tension to being in compression (meaning that the bottom chord wants to buckle). This is why it is important to make sure that the bottom chords of trusses in a sheeted roof are properly braced. Tiled roofs, on the other hand, are not as severely affected by the wind, and it is very unlikely that a simply supported truss in a tiled roof will experience any reversal of stresses in its members. This raises the question whether trusses in a tiled roof need bottom chord bracing? The question can be answered from three viewpoints: From a structural design point of view, the bottom chord should always be in tension and therefore cannot buckle.

Therefore no bottom chord bracing is required.

But from a practical point of view, if there are no bottom chord runners and cross bracing, there is nothing preventing the bottom chord from moving sideways. This makes it very difficult to do any work up in the attic space of the roof, as it is too difficult to move around with an unstable bottom chord that tends to move sideways when trying to step from one truss to another.

There is also a third point of view, namely, the requirements of the national codes SANS 10243:2004 and SABS 0163-2: 2001.

SANS 10243: 2004 clause 11.12.4 and clause 11.13.9 state that permanent bottom chord runners and bottom chord cross bracing shall be installed on all trusses where the ceiling is not directly fixed to the bottom chord and where the truss span exceeds 11.5m irrespective of the ceiling type. SABS 0163-2: 2001 Clause 7.3.4 states that tension members are to be braced at a spacing not exceeding 72mm x the thickness of the member being braced. Therefore if the timber in the truss is 36mm wide, the bottom chord needs to be braced at 72mm x 36mm = 2,592mm or 2,600mm rounded up. It is most likely that these clauses have been included in these two codes to provide for practicality and to accommodate for the possibility of reversal of stress in a sheeted roof.

So, if you have a roof where the truss span is less than 11.5m and the trusses will be getting a fixed ceiling, you do not need to provide bottom chord runners or bottom chord cross bracing.

Example of incorrect web bracing

SEPTEMBER 2015

21

B R AC I N G

transfer the buckling loads from the chords through a nailed connection into the 36x111 bracing member. The opposite is true for the same truss with an internal bearing. Therefore, from a structural design point of view, one can use the span between the outside wall to the centre of the internal load bearing wall to determine the required bracing needed for the truss. SANS 10243: 2004 clause 11.13.8.2.5 note 4 reflects this same sentiment.

Suspended ceiling

Bottom chord of truss

Suspended ceiling (no bottom chord bracing installed)

Brace

Suspended ceiling

Bottom chord of truss

Suspended ceiling (bottom chord bracing installed)

HOW DO YOU CALCULATE THE REQUIRED TOP AND BOTTOM CHORD BRACING IF THE TRUSSES ARE BEARING ON AN INTERNAL LOAD BEARING WALL? When comparing the design stresses in the members of a 15m clear span truss to that of the same truss but with an internal bearing, you will find that the stresses, especially those in the top and bottom chords, are a great deal larger in the clear span truss than the truss with the internal bearing.

Stresses in the top chord high - prefab bracing frame required

15m - Span to be used for determining bracing requirements for this truss

Truss T1 - Case A Stresses in the top chord low - no prefab bracing frame required

8.5m - Span to be used for determining bracing requirements for this truss

15m

6.5m Internal load bearing wall

Truss T1 - Case B This is the reason why bracing frames become necessary for large clear span trusses: Because the forces in the chords of the truss become so high that it is no longer possible to

22

IN A TILED ROOF, DOES ONE NEED DIAGONAL TOP BRACING IF YOU ARE GOING TO INSTALL PREFABRICATED BRACING FRAMES, AND WHAT IS THE DIFFERENCE BETWEEN A PREFABRICATED TOP CHORD STIFFENER FRAME AND A PREFABRICATED BRACING FRAME? Unfortunately it is difficult to provide a definitive answer to the first part of this question on whether diagonal top chord bracing (static stability bracing) is required if prefabricated bracing frames are going to be installed in the roof. The reason is because there are various professional opinions on the matter, and unfortunately the code (SANS 10243) is not very clear on the matter either.

With respect to the second part of this question, there is even more confusion in the industry on the difference between prefabricated top chord stiffener frames (SANS 10243 clause 11.13.8.2.5) and prefabricated bracing frames (SANS 10243 clause 11.13.11).

To come to some sort of conclusion, perhaps the second part of the question should be addressed first. At the outset, there isn’t a clear difference between a prefabricated top chord bracing frame and a prefabricated top chord stiffener frame: They both create a stiff box in the roof truss system that, in turn, is used to brace the rest of the roof back to.

To address the first part of the question, SANS 10243 clause 11.13.8.2.3 note a) serves as a reference. This clause leads one to think that static stability bracing is required if top chord stiffeners are required. Does this note also pertain to prefabricated top chord stiffener frames? Perhaps it cannot be stated so with absolute certainty, but some in the industry have interpreted it as such, and they do include static stability bracing with prefabricated top chord bracing frames.

The purpose of both bracing systems is arguable; however, there is no harm in having both systems since you then at least have a safety net in case the bracing frames are not correctly installed – which happens quite often. As already mentioned, SANS 10243 is in the process of being revised and the hope is that this issue will be resolved and clarified in the new revision.

Until such clarity is obtained, it is recommended to provide both bracing frames and static stability bracing.

DOES ONE NEED TO PROVIDE FOR STUBBED END BRACING IF THE BRICK WALL IS GOING TO GET BEAM FILL INBETWEEN THE TRUSSES? Once the brick beam fill has been completed, the stubbed end heel bracing is no longer required. The question is, at what stage will the contractor do the brick beam fill between the trusses? The stubbed end heel bracing is there to prevent the trusses from rotating at the heel. It is recommended to always include this bracing so that your roof system can stand alone without having to rely on the brick beam fill.

SEPTEMBER 2015

B R AC I N G

WHY DOES THE TOP CHORD BRACING NEED TO EXTEND TO OVER THE WALL? The top chord static stability bracing and the prefabricated bracing frames are to extend to over the wall plate. The reason for this is that the live loads that are generated by wind or the gravity loads from the dead load of the roof need to be transferred through the bracing system into the walls.

Example of a roof failing due to incorrect bracing.

WHEN DOES ONE NEED TO BOLT MULTI-PLY TRUSSES TOGETHER? Most of the time when you come across a multi-ply truss in a roof system, these trusses are girder trusses. A girder truss is a truss that carries loads from other trusses, rafters or beams that it is supporting. In some large span roofs you could come across multi-ply trusses that are not girder trusses but need to be two or more plies to be able to span the large distance from support to support. The most common types of girders are Valley girders or Hip girders. All multi-ply girders need to be joined together with M12 bolts at each node/joint of the truss, and the chords and webs need to be nailed. (For further details on the bolting and nailing of the girder plies, refer to the ITCSA’s Roof Erector’s Handbook Volume 2 page 11.) Multi-ply trusses that are not girder trusses, and where the load that they are carrying on the top chord is only from tiles or sheeting and the load on the bottom chord is only from the ceiling sheathing, do not need to be bolted or nailed as these trusses could act independently from one another. In theory, if you had a two-ply truss at a spacing of 1,000mm and you separated the two plies and placed each single truss at 500mm spacing, the trusses would still work.

Needs to be bolted at each node/joint

3 ply hip girder

2 ply trusses

Does not need to be bolted

4 ply valley girder 2 ply hip girder

Needs to be bolted at each node/joint

WHY IS IT NECESSARY TO BRACE THE TOP CHORDS OF TRUSSES UNDER A VALLEY? To be able to correctly analyse a roof truss, you need to know at what centres the top chord is braced at, as this determines the effective length of the top chord. Purlins or battens fixed to the top chord of the truss, brace the top chord, and their spacing is used to determine the effective length of the top chord. For example: You are designing a tiled roof with batten centres at 320mm centres, and there is a valley coming onto the roof from the side. The trusses below the valley that are carrying the valley trusses have been designed for a batten spacing of 320mm, but because the battens do not continue under the valley these trusses are now under designed, as the braced length of the top chord is now greater than 320mm.

If the valley truss spacing was 760mm and they were correctly attached to the top chord of the truss, one could correctly say that the top chord of the truss is now braced at 760mm divided by the cosine of the roof pitch. This still makes the truss under designed and therefore it is recommended as per SANS 10243: 2004 figure 48 that intermediate valley runners be placed under the top chords of the trusses under the valley. But even by applying this detail, one can argue that the top chords are still insufficiently braced as the braced length is now 380mm divided by the cosine of the pitch of the roof, which is still greater than 320mm. Therefore, as a note to the truss designer, it would be good practice to re-analyse the trusses under the valley for the correct top chord bracing spacing of 380mm divided by the cosine of the roof pitch to make sure that the trusses still work for this application.

Trusses

Valley trusses

Wall plate Intermediate valley runners (see notes)

s

r trus

Girde

Truss

Wall plate

IF WEB RUNNERS HAVE BEEN INSTALLED DO YOU STILL NEED THE WEB CROSS BRACING? The answer to this question is yes! If you have web runners, you still need the web cross bracing. A web runner reduces the effective length of a web and therefore makes it stiffer and less likely to buckle under its load. The compressive forces in the web that cause it to buckle are transferred into the web runner. If the runner is not attached to anything to prevent it from moving, the web can then still buckle. Therefore it is very important to cross brace the web runner to prevent it from moving. All runners, bottom chord or web, need to be cross braced.

For designers and erectors looking to gain more knowledge on roof design and bracing, the ITC-SA has set up training courses that cover roof design and bracing: Level 1 (Beginner) and Level 2 (Intermediate). For more information, contact the ITC-SA at 011 974 1061 or toll free at 0800 846 237.

The author, Errol Hobden, Pr Tech. Eng, of International Truss Systems, can be reached at 011 397 4441 or via email to adm@rooftruss.co.za.

24

SEPTEMBER 2015

FINISHING TOUCH The highest quality roof tiles at a cost effective price that enhances any building construction, only from the Technicrete Double Roman and Tuscan Roof Tiles Accessories:

Available in:

• • • • •

• •

Tapered ridge tile Angle butt ridge tile Butt mono ridge tile Angle collar ridge tile Hip starter tile

•

Colour variations Various styles and finishes Quality installation

paving | masonry | roof tiles | erosion protection retaining walls | drainage | kerbs | precast products

Technicrete is a trading division of ISG, a leading supplier of innovative infrastructure products to the construction and mining markets in Southern Africa.

Why use Rainflo PVC gutters?

Tel: 086 126 6267 www.technicrete.co.za

• They have been stabilized against UV attack • PVC gutters do not corrode or rust • They contain impact modifiers to prevent dents & cracks • Easy installation with clip in joints or solvent cement • Expansion brackets prevent distortion from movement • Time saving, easy dismantling and cleaning • Can be painted with alkyd enamel or PVA exterior paints • Square or round downpipes look stylish & modern • Lower carbon footprint when compared to other materials

Southern African Vinyls Association

CALL 0861 727 663 TO BOOK YOUR SPACE IN

+27(0)21 957 5600 +27(0)11 345 5600

info@dpiplastics.co.za www.dpiplastics.co.za

LG S ROO F S YS TE M

Ultra-Span® (LGS) roof structures submitted for Steel Awards 2015 The unique profile shapes of the MiTek® Ultra-Span® roof system ensures a low mass per m2 (between 6-10kg/m2), thereby providing savings on the supporting structure and on transportation and erection costs. Large sections of the roof can simply be pre-assembled on the ground and hoisted into position on the roof – making this one of the most viable roof systems in the range of 15m to 40m clear span structures.

SUBMITTED ULTRA-SPAN PROJECTS: MEDICLINIC MIDSTREAM • A state-of-the-art, 176-bed multidisciplinary hospital with 54 specialist, diagnostic and specialized treatment facilities – all under one roof.

• 9,100m2 Ultra-Span roof structure with some 19m-25m clear span trusses utilizing 68T of LGS at a mass of 7.5kg/m2 • Successfully supplied and completed in just 5 months by Hi-Tech Nail-Plate, a licensed MiTek roof supplier.

26

SEPTEMBER 2015

LEADING ROOF TRUSS SYSTEM SUPPLIER IN SA AND THE WORLD

Prefabricated timber roof trusses

• Light Gauge Steel Trusses • Steel Wall Framing

eCo Fasteners® are timber and steel fastening devices that provide strong and rigid connections to any building structure.

A network of more than 190 licensed roof truss manufacturers across South Africa, provides a competitive and economic solution to even the most complex of roofing problems. This MiTek fabricator network, using MiTek’s state-of-the-art software programs, provides high quality, purposeengineered truss units to satisfy the need of an ever increasing complex roof market. The scope of MiTek’s services includes not only unrivalled expertise in terms of professional structural engineering service but also the extensive Research and Development into all aspects of timber and light gauge steel roof design and construction as well as a full range of manufacturing equipment - that makes MiTek a World Leader. creating the advantage World Leaders since 1956.

MiTek Park,754 16th Road, Randjespark, Ext. 34, Halfway House,1685. Midrand (Head Office) Tel: + 27(0) 11 237 8700 Cape Town Tel: 021 905 0244 • Durban Tel: 031 700 6332 • Port Elizabeth Tel: 041 581 7525 email: marketing@mitek.co.za • www.mii.com/southafrica *MiTek Industries South Africa (Pty)Ltd, a division of the worldwide MiTek Group.

LG S ROO F S YS TE M RIVERSANDS INCUBATION HUB • This very large training/trading centre was conceptually designed with the involvement of MiTek to utilize LGS as much as possible, resulting in 85% being done using Ultra-Span.

• The 17,500m2 roof structure, comprising mostly of lattice trusses, utilized 110T of LGS with a very low mass of 6.3kg/m2 • Successfully supplied and installed by Max-Span Roofing, a licensed MiTek roof supplier.

LADY POHAMBA HOSPITAL - WINDHOEK • This mid-sized hospital project roof structure was fully designed

by MiTek, again in conjunction with the engineering firm to ensure the highest utilization of LGS. • 3,500m2 roof with shallow trusses at 1 degree pitch. Total of 24T LGS with a mass of 6.8kg/m2 of roof area.

• Successfully completed in just 32 working days – well within the allocated time frame – by Max-Span Roofing, licensed MiTek roof supplier.

FOR ADDITIONAL INFORMATION CONTACT: MiTek Industries South Africa (Pty) Ltd. (t) +27 11 237 8700 (e) marketing@mitek.co.za (w) www.mitek.co.za

28

SEPTEMBER 2015

EVERYTHING

UNDER ONE ROOF WITH OVER 65 YEARS OF ROOFING EXCELLENCE, COVERLAND HAS A SOLUTION FOR YOU.

ENERGY-SAVING

If you want to enhance the beauty of your home while ensuring its visual appeal and structural longevity, choosing the best roofing solution is paramount.

Beyond providing roof tiles that deliver both style and safety, we offer a range of products and systems to enhance and maintain your roof:

Es

Energy-Saving The RadenShield™ range of highly reflective (97%) aluminium roofing radiant barriers not only provides the benefits of a reflective insulation, but is also waterproof and reduces the amount of dust in the roof space.

RadenShield™ is a recommended component for compliance with the SANS 204 Energy Efficiency in Buildings Standard.

P

Protection

S

Sealing

T

Tiling

PROTECTION

Tired of unsightly cracked mortar along your roofs ridge and hip-line, not to mention the damage caused by leaks when it rains? Replace traditional mortar ridging with our advanced dry-fix, waterproof ridge and hip-line system which is not only aesthetically pleasing, but is maintenance free.

Our innovative EasyFlash roof sealing solution is durable, easy to install and able to hold its own against all weather conditions for up to 15 years without maintenance.

SEALING

Our extensive concrete and clay tile range has been meticulously developed to be durable in any climate, while aesthetically pleasing.

Since our humble beginnings in 1949, we’ve assisted millions of South African homeowners with our vast technical expertise and wide range of high-quality products.

When you think roofing solutions – think Coverland.

www.coverland.co.za

Enquire at your local building retailer or contact us directly:

info.sa@monier.com

TILING

A M PA CO M PA N Y N E W S

Ampa Group steadfast in superior service delivery These are exciting times within the Ampa Group, as SA Roofing learns from its CEO, Trevor Zulberg. The company is bringing new innovations to its client base, but in doing so, remains true to its old values. Values that were established more than 43 years ago and still underpin great service backed by quality products.

M

ore recent years have brought about mergers and management buyouts, but not at the cost of the integrity and competence of the technical management team.

“Since my involvement in March 2014, there have been numerous changes and simultaneously a huge effort to maintain the culture and service levels that Ampa is renowned for. I am confident in saying that we have gained a lot of ground in this space, and I am extremely happy with the progress and turnaround we have managed to achieve to date. That said, we continue to challenge ourselves with ever-higher goals, so we are not there yet,” Zulberg explains.

WORLD-CLASS BUSINESS UNIT A lot of focus has been placed on internal improvements, especially where the company’s approach to client satisfaction and product quality are concerned.

One of the most promising new implementations includes a multi-million rand software initiative that will improve client communications by means of an automated process flow. The system is already showing exceptional results in early stages of internal roll-out, and the expectation is for Ampa clients to start benefiting within the next couple of months as the external changes start having an impact. Dealings with Ampa promise to be much more efficient and enjoyable. Initiatives include the following: • Client Relationship Managers have all been issued with tablet devices, meaning client account information is now available at the click of a button. This will result in not only improved turnaround times when responding to client inquiries, but enhanced client relationships themselves, since all interactions and service commitments can immediately be recorded for action.

• A new accounts module has already gone live, ensuring that client statements, invoices and PODs are all automated and easily accessible by any authorized client representative – immediately upon request. One of the most convenient features is the ability to click on the statement and view any invoice or POD right away, without having to separately request that additional information.

30

• Another offering that is breaking ground is the paperless invoicing and POD system. This new module significantly expedites the delivery and collection of client goods and allows the Ampa logistics department access to a full tracking history – from the time of order to the time of delivery.

• Delivery drivers have also been issued with tablets, enabling authorized recipients to sign for deliveries directly on the tablet. As a result, the invoice and POD can be e-mailed without any delays.

THE BOTTOM LINE “In our current financial environment, we need to ensure that our pricing is correct and that we always stay competitive. For Ampa, more than 70% of our cost is our raw material, namely polymer. Polymer pricing is based on numerous elements, including the oil price, rand-dollar fluctuations, international supply and demand, and production quantities. One aspect we’ve identified as an area for improvement is our reaction time to the movement of polymer fluctuations. We have taken meaningful steps to respond quicker,” says Zulberg.

To this end, the company’s pricing and price lists have become automated. In turn, this improved price list module allows Ampa clients to stay up to date with Ampa’s latest prices and product range. On the first day of each month, clients now receive updated price lists (that include all products previously purchased from Ampa) with clear, convenient indications whether the prices have remained unchanged, have increased, or have decreased. Moreover, the price lists become effective only the next month, allowing at least 30 days for clients to take care of their own customer notifications. Each price list will be marked with a validity date and all orders received during the relevant period will be honoured at the associated price.

ALWAYS LOOKING TO IMPROVE “These are only a few of the changes taking place within Ampa, and the management team and I welcome client feedback to indicate a more positive experience with Ampa – or otherwise.

We acknowledge that there may be a few bumps in the road, and that not all changes will necessarily suit every other business structure. However, with our new fully automated modules we can more readily make changes and adapt to individual client needs. We invite our clients to get in touch with us to share their thoughts and suggestions,” concludes Zulberg.

SEPTEMBER 2015

www.ampa.co.za 0860 000 AMPA

OCC U PATI O N A L H E A LTH A N D S A F E T Y

Are your workers hanging by a rope?

Regulation 18: Rope Access Work is newly adopted legislation in terms of the Construction Regulations, 2014, of the Occupational Health & Safety Act, 1993 – and is of paramount importance to the construction sector.

Article by: Johan Louw, B Ing (Mech), MSc (Ergonomics) – Director, Johan Louw & Associates

Regulation 18 of the Construction Regulations, 2014, reads as follows -

Regulation 18 of the Construction Regulations, 2014, further reads -

(1) A contractor must – (a) appoint a competent person in writing as a rope access supervisor with the duty of supervising all rope access work on the site, including the duty of ensuring occupational health and safety compliance in relation to rope access work: Provided that the appointment of any such person does not relieve the construction manager of any personal accountability for failing in his management duties in terms of this Regulation.

(b) ensure that all rope access work on the construction site is carried out under the supervision of a competent person, and (c) ensure that all rope access operators are competent and licensed to carry out their work.

It is important to understand that the ropes referred to in this Regulation do not fall within the definition of “lifting machinery” or “lifting tackle.” However, it is highly recommended that these ropes be treated in accordance with the requirements of Regulation 18 of the Driven Machinery Regulations, as the consequences of failure thereof would be the same – e.g. fatalities, injuries, loss of production, litigation, etc.

34

One can reasonably assume that the “supervision of a competent person” referred to in the above-mentioned sub-regulation (1)(b) is intended to mean the person contemplated in the above-mentioned sub-regulation (1)(a) – in other words, the competent person in writing as a rope access supervisor.

It is not clear what the intention of the legislature is with the term “licensed” being used in paragraph (c). It is safe to assume that the person must be in possession of a training certificate which was issued by an approved or accredited organization.

SEPTEMBER 2015

• the management of the physical construction processes; • coordination, administration and management of resources on a construction site; • managing all the construction work on a single site; • the duty of ensuring occupational health and safety compliance; and • be in possession of the most recently updated version of the fall protection plan. This is an implied obligation, as Regulation 10(3) requires that the contractor must ensure that the construction manager is in possession of the most recently updated version of the fall protection. Therefore it implies that a construction manager has a duty regarding the fall protection plan, which is to ensure such plan is developed and implemented. That is exactly why subregulation (1)(a) stipulates that the construction manager is not relieved of any personal accountability for failing in his management duties in terms of this Regulation.

Furthermore, the scope of service of a construction health and safety manager, as defined by The South African Council for the Project and Construction Management Professions (SACPCMP), entails the following: • Designing and developing organizational health and safety management systems.

• Leading and managing the implementation and maintenance of health and safety systems.

• Leading and managing the optimization of compliance with the organizational health and safety management system.

• Providing assurance of the effective management of health and safety within the organization.

• Measure, audit and evaluate the effectiveness of hazard controls and hazard control programmes.

• Analyse incidents to identify deficiencies in the health and safety management systems and produce management reports.

OCC U PATI O N A L H E A LTH A N D S A F E T Y

It is interesting to note that a contractor must also ensure that a construction manager appointed under Regulation 8(1) of the Construction Regulations, 2014, is in possession of the most recently updated version of the Fall Protection Plan as contemplated in Regulation 10(3) of the Construction Regulations, 2014. No other “specific” duties are imposed on the construction manager per se, but one has to bear the definition of a “construction manager” in mind, which stipulates the following duties:

Regulation 18 of the Construction Regulations, 2014, further reads – (2) No contractor may use or allow the use of rope access work unless – (a) the design, selection and use of the equipment and anchors comply with the safety standards incorporated for this purpose into these Regulations under section 44 of the Act, and (b) he or she is in possession of a site specific fall protection plan developed by a competent person applicable to the specific work and environment prior to the commencement of the work, including records of maintenance and inspections of all the equipment used for the work operations.

No health and safety standard in relation to rope access work has been incorporated into the Construction Regulations, 2014, as contemplated in sub-regulation (2)(a), and neither is any such standard defined in Regulation 1 of the said Regulations. It is therefore recommended that the following Health and Safety Standards be implemented: • SANS 10333-1:2006 entitled “Industrial rope access Part 1: Worksite procedures” • SANS 10333-2:2006 entitled “Industrial rope access Part 2: Training and certification procedures” • SANS 10333-3:2006 entitled “Industrial rope access Part 3: Inspection, certification and management procedures for equipment” Regulation 18 of the Construction Regulations, 2014, further reads (3) A contractor must ensure that adequate measures are in place to allow rescue procedures to commence immediately in the event of a fall incident taking place.

The requirement stipulated in sub-regulation (3) is an aspect that is already an obligation of the contractor, as contemplated in Regulation 10(2)(e), of which it requires that a rescue plan be part of the Fall Protection Plan.

It is important to garner an understanding and acquaint yourself with the necessary knowledge of amendments as it relates to rope access work, so as to ensure legal compliance on construction sites.

For more information, contact Johan Louw with Johan Louw & Associates on 012 998 4102 or visit www.jla-solutions.co.za.

SEPTEMBER 2015

35

ROO F I N G M AT TE R S : FA S TE N E R S

Roofing matters…

Fasteners matter - greatly Don’t underestimate the critical role of roofing fasteners when it comes to the overall performance of a roofing system. In this instalment of our series that brings you practical insight from the experts, we learn more from Reitze Hylkema, Managing Director of Kare Industrial Suppliers, on how to select a suitable fastening system that won’t fail.

T

oo often, proper attention is given to fastener selection only after fasteners have failed and problems start to occur. This is unfortunate because, by following a few straightforward guidelines upfront when choosing fasteners and corrosion-resistant coatings, you can make the correct selection to ensure that the fasteners don’t become the weak link in the roofing system.

No.1 point: Stitching of thin gauge material (i.e. flashing and sheeting; end laps and side laps) and fixing into thin gauge metal battens.

Since the publication in November 2009 of the revised standard relating to roofing fasteners, namely SANS 1273, the roofing and cladding market has been offered a wider range of corrosion-resistant coatings on roofing fasteners. However, the roofing professional should be aware: Despite some rather exaggerated performance claims by the importers, a lot of available fasteners do not conform to the SANS 1273 coating requirements.

No.3 point: 4.5mm drilling capacity. This is by far the most popular drill point and commonly used for fixing sheeting to 2.5mm cold rolled lip channel.

FASTENER SELECTION While more outdated types of fasteners are still being used in the roofing market and are still listed in SANS 1273, self-drilling type fasteners are increasing in popularity and are the focus of this article.

No.2 point: 2.5mm drilling capacity in cold rolled steel.

No.5 point: 12.5mm drilling capacity.

This drill point is used on hot rolled steel sections.

3. When fixing fibreglass, polycarbonate and fibre cement sheeting, an oversized hole in the sheeting is required to allow for expansion and contraction of the sheeting. By using a winged self-drilling screw, the reaming process can be done while fixing the fastener.

Factors to consider when assessing roofing fasteners include: 1. Fastener point selection 2. Fastener head selection 3. Fastener length calculation 4. Corrosion considerations 5. Material compatibility

FASTENER POINT SELECTION The drill point diameter is in correlation with the thread diameter and influences the pull-out values obtained in different steel thicknesses.

FASTENER HEAD SELECTION When IBR and corrugated profiles are fixed, the fasteners are fixed through the sheeting into the purlins. This is referred to as a pierced-fix roofing system. Either hexagon head, hex washer head or hex flange head screws are used for pierced-fix applications.

Hexagon head and hex washer head screws: Used in combination with bonded washers.

Hex flange head screws: Normally assembled with a rubber seal not requiring an additional bonded washer.

To select the correct drill point, you need to know if the screw will be drilling into timber, steel, or another material.

1. If fixed into timber, use a screw with a Type 17 point: 2. If fixed into steel, use a screw with a drill point that has the correct drilling capacity.

36

Hexagon head

Hex washer head

Hex flange head

SEPTEMBER 2015

CORROSION RESISTANCE CLASS

1. Pierced fixing: You must add the following numbers in order to calculate the correct fastener length for pierced fixing through the crest of the sheeting: • The profile height of the sheeting.

• The thickness of washers and seals.

• The compressed thickness of insulation material between the sheeting and the purlin.

• The thickness of the purlin in the case of steel purlins.

• The length of the drill point and the first three threads above the drill point in the case of steel purlins.

• 35mm penetration into the timber in the case of timber purlins.

The length obtained is the recommended length of the fastener.

If this is not a standard length, then the next longer standard length is recommended.

When fixing through the valley (pan) of the sheeting, the same calculation applies, but the profile height is omitted.

ATMOSPHERE OF INTENDED USE

1

General use in internal application

2

Internal applications with significant condensation levels; External applications: Inland rural & mild urban

3

External use in moderate industrial or marine environments

4

External use in severe industrial or marine environments

5

External use in very severe industrial or marine environments

FASTENER LENGTH CALCULATION

Only Class 2 and higher classes apply to external roofing. The specification of the coating for self-drilling screws in these categories is as follows:

COATING

MINIMUM LOCAL METALLIC COATING THICKNESS (μm)

CORROSION RESISTANCE CLASS

MINIMUM POROSITY RATING

2

-

Electroplated 98% Zinc Zinc

12

3

-

Electroplated 98% Zinc Zinc

30

3

8

Mechanically plated Zinc

98% Zinc

40

3

8

Mechanically plated Zinc/Tin

20-23% Tin. Balance Zinc

25

4

8

Mechanically plated Zinc/Tin

20-23% Tin. Balance Zinc

45

2. Concealed fixing: When fixing concealed-fix roofing systems, the correct fastener length is calculated as follows: • The compressed thickness of insulation material between the sheeting and the purlin plus the height of any packers between the insulation and the purlin.

• When fixing into steel purlins, add the thickness of the purlin, the length of the drill point and the first three threads above the drill point.

• When fixing into timber purlins, add 35mm for penetration into the timber.

ROO F I N G M AT TE R S : FA S TE N E R S

With concealed-fix roofing systems a clip, bracket or halter is fastened onto the purlin, and the sheeting is clipped, hooked or seamed onto the clip. These systems allow the sheeting to expand and contract without movement Wafer head restriction caused by pierced fasteners. As a result, much longer continuous spans can be rolled. Most of the concealed-fix roofing system requires a wafer head fastener that fits flush in the recess of the clip.

COATING TYPE

COMPOSITION

(BY MASS)

Note: SANS 1273–2009 lists sherardizing and hot dip galvanizing as suitable corrosion-resistant coatings for fasteners other than self-drilling and self-tapping screws.

COMPLIANCE TESTING In order to prove compliance with the corrosion-resistant coating requirements of the standard, at least one of three testing methods must be conducted:

CORROSION CONSIDERATIONS

1. Accelerated laboratory testing.

The corrosion resistance requirements of roofing fasteners as described in SANS 1273–2009 draws on the information published in the Australian Standard AS3566.2-2002. In the standard, corrosion-resistant coating types, thicknesses and compositions are specified and linked to environmental categories.

2. ‘Deemed to comply’ based on the porosity rating, the coating thickness and the coating composition.

3. Real-world testing.

The environmental categories are based on ISO9223, which lists the following corrosion resistance classes:

SEPTEMBER 2015

37

ROO F I N G M AT TE R S : FA S TE N E R S

ACCELERATED LABORATORY TESTING Accelerated laboratory testing is conducted according to AS3566.2-2002 and requires salt fog tests and sulphur dioxide (Kesternich) tests to be performed on metallic-coated selfdrilling screws.

Salt spray tests attempt to simulate a marine environment and to test the effect of salt-laden air on fasteners. Sulphur dioxide tests try to simulate an industrial environment and to test the effect of industrial fall-out on fasteners.

Another drawback of laboratory tests pertains to the interpretation of test results. If a fastener passes a 1,000 hour salt spray test, what does it really mean? How long will that fastener last if it is used on a shopping mall roof in a coastal town? If a fastener passes 15 cycles in a Kesternich test, how long will it last when used on the roof of a chemical factory?

The laboratory tests cannot provide these answers, and therefore are in essence best limited to comparative testing.

The fasteners being tested are first driven into a 1.5mm-thick galvanized steel plate and removed, or, in the case of screws for timber, the screws are driven a minimum of 30mm into untreated pine and then removed. Only after this procedure can the screws be tested.

The fasteners must pass the following tests without showing signs of red rust on more than 5% of the head and shank of the self-drilling screw.

MINIMUM HOURS IN NEUTRAL SALT FOG TEST

MINIMUM HOURS IN SFW 2.05 SULPHUR DIOXIDE TEST

Class 2 fasteners

240 Hours

5 Cycles

Class 3 fasteners

1000 Hours

15 Cycles

Above: Laboratory test cabinet

It is important to note that accelerated laboratory testing is not listed in the standard as a method to test Class 4 coatings.

Also, it bears mentioning that, while laboratory tests can be quite useful to obtain comparative test results done between different fasteners, there are some inherent flaws in this type of testing. For example, these tests only test performance in one specific type of environment, being either marine or industrial, whereas fasteners in industrial areas are often also in close proximity to the coast (think of areas like Richard’s Bay, Durban, Cape Town and other coastal cities). A combination of ultra-violet radiation, condensation and industrial pollution can also contribute to high corrosion rates (Gauteng and Mpumalanga regions), but such environments cannot be duplicated in laboratory tests, meaning the results are not a completely true reflection of how fasteners will perform in reality.

Moreover, laboratory tests are conducted at a temperature of 35°C but in the real world, temperatures on a roof might reach 80°C. As corrosion rates increase at higher temperatures, the actual corrosion rate will therefore often be much higher than the results obtained in laboratory tests.

Thirdly, when fasteners are tested in a laboratory they are tested in isolation – they are not in contact with a roofing washer, roof sheeting or clip, insulation or the purlin. All these dissimilar materials that make up the complete roof structure lead to galvanic cell corrosion in the real world and will affect the service life of roofing fasteners. Again, laboratory tests cannot provide completely reliable results on which to determine the expected life span of a fastener.

38

Above: Fasteners sold in South Africa as Class 4 tested by SABS failed dismally in salt spray test.

DEEMED TO COMPLY Fasteners are ‘deemed to comply’ with the standard based on three criteria: Whether or not the coating thickness, the coating composition and the coating porosity conforms to the specifications of the table in the standard. This method of testing can be used for Class 2, Class 3 and Class 4 fasteners.

The rationale behind this method is that if a coating contains a specified percentage of zinc or zinc and tin, and the coating has a specified thickness and a porosity rating of at least 8 on the scale given in the standard, then the screws will be suitable for use in specific environments.

Above: Coating thickness.

SEPTEMBER 2015

• The coating thickness must be measured on the flange of the head of the fastener or on the side of the hexagon head. On wafer head screws, the thickness must be measured on top of the head. Three separate readings must be obtained and all three must meet the standard requirement.

• The coating composition of zinc/tin coatings must be analysed. The tin content must make up between 20% and 23% of the coating, with the balance in zinc.

• The porosity of mechanically plated screws must be inspected by placing a cross-section of the coating under a microscope with a magnification of 500X and comparing the image with the images listed in the standard as shown below. A rating of 8 is required to comply with the standard.

The zinc loss of the coupons is monitored at regular intervals.

ROO F I N G M AT TE R S : FA S TE N E R S

In order to achieve compliance this way, the following tests are required:

• Testing Class 3 screws: Once the coupons have lost 21 microns of zinc, 95 out of 100 screws that are tested must show no signs of red rust on the head and/or shank of the fastener. Put another way, if red rust shows on more than 5% of the fasteners as described, the fastener has failed.

• Testing Class 4 screws: For this class, the above rule applies once the coupons have lost 42 microns of zinc.

Where the ‘deemed to comply’ method falls short is in the fact that there is no government institution or independent authority that monitors the true quality of coatings that is sold to the South African market. Very few fastener manufacturers/ importers in South Africa provide reputable and independent test results that confirm compliance to the ‘deemed to comply’ table of the standard. In fact, many fastener distributors have no test results at all, while others present dubious and misleading reports.

The three applicable tests all have to be done in a laboratory with relatively expensive equipment, which makes the continuous testing of fasteners an expensive exercise.

But irregular testing defeats the purpose of testing, as porosity and tin content in fasteners tends to be very inconsistent. Clearly a more effective option is to test fasteners where they will be used, meaning outdoors in the real world, exposed to harsh conditions, under varying temperatures, and in contact with other roofing materials.

Above: Covered (unwashed) real-world test panel in marine environment.

REAL-WORLD TESTING Real-world testing is the most reliable and realistic method of testing as it combines the fasteners, the washers, the roof sheeting and the trusses in contact in an aggressive environment that can combine varying temperatures and conditions.

On a real-world test site, zinc coupons are fixed on the same exposure rack as the fasteners and sheeting. The test racks comprise exposed and sheltered panels to simulate the effect of rain washing the fasteners and roof sheeting – an aspect that has a big influence on corrosion (sheltered being worse).

SEPTEMBER 2015

Above:The top row shows the zinc coupons used as the corrosion rate indicator.

(NOTE: The real-world test site shown here is located at King Island, Australia. This test site is run by ITW Buildex, and corrosion results are independently monitored by the Australian CSIRO.)

39

ROO F I N G M AT TE R S : FA S TE N E R S

MATERIAL COMPATIBILITY When selecting fasteners, it is important to ensure that both the fastener and the corrosion-resistant coating are compatible with the roof sheeting. If not, the result will be galvanic corrosion. It is therefore advisable to carefully read the specifications of the sheeting manufacturers. Often the warranty on sheeting material is subject to the correct fasteners being used.

As a general guideline, the following combinations of fasteners and roof sheeting are recommended:

Class 2 Zinc electroplated ZINC COATED STEEL

X

X

ZINC ALUMINIUM COATED

X

X

PAINTED ZINC COATED STEEL

X

X

PAINTED ZINC ALUMINIUM COATED

X

X

ALUMINIUM & PAINTED ALUMINIUM STAINLESS STEEL & PAINTED STAINLESS STEEL

X

Class 3 Class 4 Class 5 Mechanically Mechanically Stainless plated plated steel

X

VALLEY FIXING, LONG SPANS, FILINGS AND MORE There are some additional factors to consider when selecting fasteners: Valley fixing does not allow for expansion and contraction of the roof sheeting and will result in the hole around the fastener becoming elongated, leading to possible leaks. In addition, rain runs off the crest of the sheeting and into the valley, and fastener heads will form an obstruction in the valley behind which debris will accumulate. This will lead to premature corrosion of the sheeting behind the fasteners. Therefore, in pierced-fix roofing applications, it is advisable to fix the screws through the crest of the profile and not through the valley (pan) of the sheeting.

Is not advisable to use pierced-fix roofing systems on spans longer than 18m, as expansion and contraction will cause fasteners to work loose over time and strip the holes in the purlins. This span length is reduced when fixing into thin gauge metal battens. For longer spans, concealed-fix roofing systems are recommended.

All swarf and metal filings should be removed from the roof sheeting after the roofing fasteners have been installed, as these filings will cause corrosion and damage the roof sheeting very quickly.

X

X

If using dissimilar metals together is unavoidable, it is advisable to use a non-conductive sleeve around the fastener to prevent contact between the fastener and the sheeting. This is essential, especially in highly corrosive environments. Usually this will necessitate the pre-drilling of an oversized hole in the sheeting to accommodate the sleeve.

If bonded washers are used, it is important that the corrosion resistance of the washers matches that of the fasteners and the roof sheeting. Non-conductive rubber should be used on washers to eliminate the problem of pit corrosion, especially on zinc/aluminium-coated sheeting and aluminium sheeting.

BE SURE, NOT SORRY Selecting the correct fastener type and appropriate coating before the start of the project will prevent costly repairs and eliminate problems caused by premature corrosion in the long run. If there is any doubt about which fasteners and/or coatings to use, consult with the roll former or a reputable, specialist fastener supplier.

FOR MORE INFORMATION, CONTACT THE AUTHOR REITZE HYLKEMA AT: Kare Industrial Suppliers (t) (011) 334-0922 (e) reitze@kare.co.za (w) www.kare.co.za

Above: A 316 stainless steel fastener in contact with a painted zinc /aluminium-coated steel roof sheet, resulting in corrosion.

40

SEPTEMBER 2015

ZAP FASTENING SYSTEMS OFFERS YOU: The widest range Guaranteed quality and performance Best value for money Nationwide distribution

ZAP FASTENING SYSTEMS ARE SUITABLE FOR ALL ENVIRONMENTS Z2 ELECTROPLATED SCREWS

Z3 DUPLEX COATED SCREWS

Made to SANS1273 Class 2 specifications for use in mild rural and urban areas. Compatible with Z275 sheeting

Made to SANS1273 Class 3 specifications. For use in moderate marine and industrial environments.

Compatible with Zinc Aluminium coated sheeting

Z4 DUPLEX COATED SCREWS

Z5 BI-METAL STAINLESS STEEL SCREWS

Made to SANS1273 Class 4 specifications. For use in severe marine and industrial environments.

Compatible with painted Zinc and painted Zinc Aluminium coated sheeting

Made for ISO9223 Class 5 environments. For use in very severe marine and industrial environments.

Compatible with stainless steel and aluminium sheeting

ZAP FASTENING SYSTEMS HAVE A VARIETY OF HEAD STYLES AND DRILL POINTS FOR ALL APPLICATIONS

ZAP FASTENING SYSTEMS RANGE FROM 13MM TO 180MM IN LENGTH

Zap fastening systems are distributed nationwide by KARE INDUSTRIAL SUPPLIERS Johannesburg (011) 334 0922

Durban (031) 705 5610

Cape Town (021) 592 4577

Pretoria (012) 332 4073

Port Elizabeth (041) 451 1447

S TE E L AWA R DS 2 015 W I N N E R S

The Spectacular Steel Awards 2015 Winners 42

SEPTEMBER 2015

S

teel Awards 2015 was held simultaneously in Johannesburg, Cape Town and Durban on September 3rd. The sponsors were: Main – AVENG Steel; Table decor – Peddinghaus; Photo competition – Cadex Systems SA; Tubular category – The Association of Steel Tube and Pipe Manufacturers; Light steel frame category – Saint-Gobain; Metal cladding category – Global Roofing Solutions; Factory and warehouse category – B&T Steel; Partner sponsors – ArcelorMittal SA, EVRAZ Highveld Steel & Vanadium, Genrec Engineering, Macsteel, and NJR Steel.

OVERALL WINNER AND TUBULAR CATEGORY WINNER: SKA AFRICA RADIO ANTENNA POSITIONER The SKA Africa Radio Antenna Positioner was the Overall Winner at Steel Awards 2015. It was also the winner of the Association of Steel Tube and Pipe Manufacturers (ASTPM) Tubular Category. This is the second year in a row that the overall winner comes from this category.

The judges said this project “radiates excellence not only in the use of structural steel but in every aspect of its structure and purpose.”

Part of South Africa’s technical capability displayed in the bid for the SKA was backed up by the design and build of the seven dishes for the SKA Africa Telescope. This ‘mini-SKA’ has in itself displayed excellence, delivering images of the galaxy Centaurus A, 13 million light years away.

The SKA Africa programme is for 64 antenna positioners to be completed by late 2016 on a site 90 kilometres from Carnarvon, Northern Cape, without mobile phone contact and far from engineering resources, so that by mid-2017 the SKA will be doing scientific work.

Each receptor consists of three main components: The antenna positioner, which is described as a steerable dish on a pedestal (the judges thought this in itself was superb use of steelwork), a set of radio receivers, and the associated digitisers. The judges noted that the enormous complexity of the geometry for the antennae “must surely compete with last year’s overall winner, the Malapa project, which was complex but was built with the luxury of our normal two millimetre structural tolerances.”

The antenna positioner allows for a vertical (tilt) range of 15° to 88°, and an azimuth range of 360 degrees - to an accuracy of within 1.4 thousandths of a degree under optimal conditions and 7 thousandths of a degree during normal operational conditions.

SEPTEMBER 2015

S TE E L AWA R DS 2 015 W I N N E R S

Steel Awards 2015 has come and gone, and according to Awards Convenor, the Southern African Institute of Steel Construction’s (SAISC) Spencer Erling, the quality of the entries easily matched the outstanding quality of previous years. “We are going through very tough times in the steel construction industry. Yet, in spite of this, we are able to produce world-class work—an indication that the future is a bright one,” he said.

“That’s a degree of accuracy that is hard to grasp for structural engineers, given the fact that we normally work to the nearest two millimetres,” the judges noted.

The largely tubular antennae support structure was, by choice of the fabrication team, built with zero tolerance targets. “The engineering, detailing, jig fabrication and construction move these structures into a different league from your run-of-themill tubular truss-type project. The accuracy of dimensions after erection is critical to give the radio telescope maximum chance of achieving its unimaginable expected accuracy,” the judges said.

Small tube connections use overlapping Tee connections. The larger bores, with higher loads, where an eccentricity in the Zed direction could lead to moments in the connection, have been designed with cover splice plates to the Tee joints, thereby ensuring no eccentricities occur. This type of structure is the perfect application for the use of circular hollow sections.

Careful detailing enables the centre of gravity lines of the elements to meet in a common centroid. In some connections there are as many as 11 framing members.

The pedestal fabrication is largely out of plate, and the interface between the pedestal and yokes of the support structure are line bored. Pedestals are erected before the antennae framework. The frame is offloaded and erected directly from truck to pedestals.

“A scientific project of this nature that taxes the skills of South African engineers and scientists to rise above the challenges and make it work, represents excellence in every way, but it is especially a triumph in the use of steelwork and is truly deserving of being the Overall Winner of Steel Awards 2015,” the judges concluded.

PROJECT TEAM CLIENT/DEVELOPER: SKA Africa MAIN CONTRACTOR/PROJECT MANAGER: General Dynamics SATCOM Technologies STRUCTURAL ENGINEER: General Dynamics SATCOM Technologies, Vertex Antennas (Germany) STEELWORK CONTRACTORS: Tricom Structures BUS STRUCTURE: Tricom Structures (a subsidiary of Robor) PEDESTAL: Efficient Engineering STRUCTURAL STEEL DETAILER/DETAILING COMPANY: Tricom Structures (a subsidiary of Robor) PAINTING: Joesa Painting

43

S TE E L AWA R DS 2 015 W I N N E R S BRIDGE CATEGORY WINNER: KIRSTENBOSCH CANOPY WALKWAY (“THE BOOMSLANG”) In praising this outstanding structure, the judges said it was a true team effort. “The end result is an efficient, flowing structure that provides the visitor with a truly memorable experience,” they noted.

The brief could be summarized in a few words: To design a pedestrian bridge between the tree tops of the Arboretum at Kirstenbosch. But the project was indeed a challenging one and is the ‘story’ of how well the whole project team worked together to realize the brief.

The walkway was designed to be ‘organic’ and blend unobtrusively into the forest, while minimizing damage to the trees. To achieve this, a delicate structure, carefully located between the trees, and finished in a colour that would blend in, was required. “Steel was clearly the material of choice to satisfy these criteria,” the project team said.

To minimize disruption and damage to the vegetation, a comprehensive survey of the area was undertaken. Columns were located relative to trees, and were not necessarily placed at the most efficient structural support positions. Where it wasn’t possible to avoid a particular tree, it was either allowed to pass through the structure or was tied back to ensure that it experienced minimum interference from the structure.

The spine of the structure, a single tube section, forms the bottom chord of a truss. The box section handrails double as the top chords of the left and right trusses. Ribs cut from 8mm plate at 1m centres serve both as stanchions and as the vertical elements of the trusses. The ribs are made up of three parts bolted together below the deck.

44

This ensures efficient use of material, facilitates handling in the confined areas between trees, and also limits the use of heavy equipment in this sensitive area. All components were preassembled in the workshop and, when installed on site, everything fitted perfectly – no on-site cutting or welding was required.

Since being opened to the public, the Boomslang has proven to be extremely popular. The increase in gate income from more visitors allowed the capital costs of the bridge to be recovered within one year of it being opened. This fact influenced the judges who said: “The project not only met the professional team’s requirements and was aesthetically and practically outstanding, but it also increased the number of visitors to the Gardens by more than 30%, thus making it a resounding commercial success. It thoroughly deserved the Bridge Category Award.”

PROJECT TEAM CLIENT: SANBI (South African National Biodiversity Institute) ARCHITECT: Mark Thomas Architects, in Association with Christopher Bisset STRUCTURAL ENGINEER: Henry Fagan & Partners QUANTITY SURVEYOR: Bernard James & Partners Quantity Surveyors MAIN CONTRACTOR: Slingsby & Gaidien Construction STEELWORK CONTRACTOR, DETAILERS: Prokon Services LAND SURVEYOR: Stern & Ekermans GALVANIZER: Advanced Galvanizing CORROSION PROTECTION CONSULTANT: Koning Vadas Blom Associates

SEPTEMBER 2015

S TE E L AWA R DS 2 015 W I N N E R S

JOINT WINNERS OF LIGHT STEEL FRAME CATEGORY: HOUSE DE CLERCQ AND COTTAGE, AND MEDICLINIC Nothing better emphasizes the coming of age of LSFB (light steel frame building) in South Africa than the record number of LSFB project entries for Steel Awards 2015. The judges had great difficulty choosing between these two stellar projects, so they opted for Joint Category Winners in the Saint-Gobain Light Steel Frame Building Category.

HOUSE DE CLERCQ AND COTTAGE, MOUNT VERDE, KZN Set in an agricultural estate, surrounded by sugar cane, this house is a perfect example of what LSFB methods are meant for. “It is true to the material and does not look like a LSF house trying to look like a brick home. The early involvement of the contractor with the design team enabled them to push the limits of LSFB,” the judges commented.

“With a clever mix of a LSF system, with plated LSF joists and some hot rolled steel, they were able to achieve the client’s desire for an industrial look with thin sharp lines to produce a world-class, beautiful, upmarket home,” said the judges.

SOME OF THE FEATURES: • Hot rolled steel: Structural steel H-sections form the structure of the centre living area, the main façade, and three patio areas.

• Exposed LSFB construction, finished in black paint: Even in the double garage there is exposed LSF in its original galvanized finish, with a light steel frame storage rack hanging off the roof - such a simple, practical idea!

SEPTEMBER 2015

• Large glazed openings to capture the stunning view: Glazing and opening sizes were a challenge, as the client wanted maximum clear views and wide-opening spans. This was achieved using a combination of doubling up LSF joists and plating them with 1.0mm thick galvanized sheet and L-headers.

• An indoor/outdoor Koi pond: This feature helps to create the feeling of ‘openness’ with its glass panel partly submerged in the water.

• Exterior wall cladding: This was done with flat fibre cement board with a fine-texture plaster finish and imported tongue-and-groove Shera plank.

• Interior walls: These were cladded with Gyproc 15mm Firestop boards and 102mm cavitybatt insulation in the wall cavity.

“We have had many houses entered into Steel Awards since we started this category, but this house, more than any others, highlighted all those wonderful attributes that make the LSFB product so special,” the judges concluded.

PROJECT TEAM CLIENT: Kim and Paul De Clercq ARCHITECT: Earth Energy Architecture STRUCTURAL ENGINEER: Martin & Associates MAIN CONTRACTOR, LSF CONTRACTOR, PROJECT MANAGER, CLADDING ERECTOR: Shospec STEELWORK CONTRACTOR: Barnmaster STRUCTURAL STEEL DETAILER/DETAILING COMPANY: Steel Frame Developments (light steel frame roll former)/Martin and Associates & Barnmaster (for structural steel) CLADDING SUPPLIER: Capco

45

S TE E L AWA R DS 2 015 W I N N E R S MEDICLINIC, MIDSTREAM, CENTURION Due to the early involvement of the LSF contractor and profile supplier, the architect was convinced that the design should include a LSF roof structure to reduce the total load on the supporting structure.

The Ultra-Span (a pre fabricated light gauge steel roof truss system by MiTek) roof structure covers 9,100m² of the roof structure and weighs in at almost 68 tons of steel. This comes to just under 7.5 kilograms per square metre, including purlins, which is extremely light, considering some of the roof trusses span 19 metres with considerable live load and bottom chord loading requirements. The design also allowed for supporting 100mm-thick FBI insulation between the truss top chords and the purlins.

The long span, Ultra-Span trusses were assembled on site, thereby eliminating transport problems of the large components. Smaller units were assembled in the factory and delivered to site.

“This project is an excellent testimonial for light steel frame roofing,” the judges observed. “It illustrates all the beneficial aspects of steel – formability, guaranteed high strength, low mass, straight and true elements, narrow tolerances, ease of transport, handling and erection, with lifelong corrosion protection supplied by the thin zinc coating. And to top it all, the cost of the light steel roof structure was 50% lower than timber trusses, and 30% lower than what welded heavy steel trusses would have cost! It is no wonder that the use of light steel roof structures such as Ultra-Span is growing so rapidly, replacing timber, and even competing with heavy steelwork in certain cases,” they concluded.

46

PROJECT TEAM CLIENT: Mediclinic ARCHITECT: Graceland Architects STRUCTURAL ENGINEER: Cibucon Structural Engineers QUANTITY SURVEYOR AND PROJECT MANAGERS: TMS Quantity Surveyors MAIN CONTRACTOR: Basil Read LSF CONTRACTOR, DETAILER, SUPPLY OF PROFILES: Ultra-Span LGS - MiTek Industries South Africa (Pty) Ltd CLADDING CONTRACTOR: Rainbow Sheeting

SEPTEMBER 2015

S TE E L AWA R DS 2 015 W I N N E R S

LSFB CATEGORY COMMENDATION: KURUMAN CASINO FAÇADE The judges observed that local architects and engineers have, in the last few years, recognized the insulating values and architectural flexibility offered by the Light Steel Frame Building (LSFB) and External Thermal Insulation Composite System (ETICS) systems.

The 300m² Kuruman Casino façade is supported on a light steel framed structure that was factory built. Sheathing comprising OSB board was fixed to the frame and covered by a vapour permeable membrane, which was in turn fixed to the sheathing, followed by EPS insulation boards. The EPS board was then primed and sealed with a decorative acrylic resin topcoat. The external insulation results in a ‘warm frame’ that prevents condensation on the steel frame, adding to the durability of the structure. The project team said that ETICS provided the flexibility to create the intricate features of the architects’ design with attractive, durable finishes.

“This is a great example of an ETICS façade, which product has been described as the future of architectural cladding. This project is more than worthy of a commendation in the Saint-Gobain Light Steel Frame Category,” the judges concluded.

PROJECT TEAM CLIENT: Kuruman Casino ARCHITECT: FFA Architects (Pty) Ltd LSF CONTRACTOR, STRUCTURAL ENGINEER, DETAILER, CLADDING ERECTOR: Razorbill Properties 127 (Pty) Ltd MAIN CONTRACTOR: W.F. Kroon CLADDING SUPPLIER: Saint-Gobain Weber SA

SEPTEMBER 2015

47

S TE E L AWA R DS 2 015 W I N N E R S WINNER RESIDENTIAL CATEGORY: ZINKWAZI BEACH HOUSE Located on the steep eastward-facing slopes above the Zinkwazi beach, the judges said that this gem, using glass window walls framed by an exposed structural steel structure, has unimpeded views from the living spaces. “It was an absolute pleasure judging this home. Even more of a pleasure was to see first-hand the innovative, yet functional use of steel finished off by some skilled and very neat fabrication,” they said.

The expression of this building is derived directly from the usage requirements – enclosed spaces are built in concrete and masonry, and open or transparent spaces are constructed from steel and glass. “These structural systems define the aesthetic language of the building and speak directly to the functional aspects of the spaces that they enclose,” the project team noted.

The proximity to the coast required careful attention to the coating of the steel. Steel with a high specification duplex paint coating system was therefore used. The balustrades are fabricated from stainless steel.

Some important features of this home: • It is designed to be almost self-sufficient in terms of electricity and water supply.

• Photovoltaic solar panels mounted on the roof charge a bank of batteries connected to an inverter system.

• Water is heated by solar collectors and a heat exchanger.

• Passive shading devices protect the glazing from the sun.

• The ability to recycle structural steel also contributes to the green building philosophy.

48

The judges stated that, due to the slenderness of the structure and the architectural requirement stipulating all connections to be visible within the living area, careful attention was given to the design of all connecting and bracing elements. “This required close cooperation at the design stage between architect and engineer. As a result, the architecture and structural detailing were inter-dependent, leading to the uniqueness of this winner,” they said. “It is a great example of what can be achieved using our material of choice.”

PROJECT TEAM ARCHITECT: John Smillie Architects STRUCTURAL ENGINEER: Young + Satharia QUANTITY SURVEYOR: Cardwell & Wonfor Quantity Surveyors MAIN CONTRACTOR: Vista Construction STEELWORK CONTRACTOR: Impact Engineering

SEPTEMBER 2015

HENNIE DE CLERCQ HOUSE The key notion behind the de Clercq house, situated on the slopes of Table Mountain in Cape Town, is that of outside living, with ‘outside’ incorporating essentially everything on the ground floor, with as few boundaries as possible. Thus the single, large living room, encompassing the kitchen, dining and lounge area, opens to the patio on the one side and onto a wide ‘stoep’ without columns on the other, bordering on the fynbos garden.

A structure consisting of I-section beams and columns enables the open plan and the cantilever stoep, while carrying most of the storey above.

Much attention was given to the details and finishes of this structure as it constitutes a key architectural feature.

Just as the ground floor is intended to be as open as possible, so the first floor, containing the bedrooms and study area, is intended to be a safe, warm refuge. The floor structure is made of cold-formed lipped channels and the walls and roof of light steel frame construction. The roofs are clad with concealed fix sheeting.

PROJECT TEAM

Tugela Bridge – Winner of the Bridge category at the 2014 Steel Awards

CLIENT: Dr and Mrs H. de Clercq ARCHITECT: Debbie Preller STRUCTURAL ENGINEER: Barend Oosthuizen PROJECT MANAGER: Owner STEELWORK CONTRACTOR: Union Structural Engineering Works (Pty) Ltd

The balustrade of the staircase is made of 4.5mm-thick steel plate, unpainted, supporting the wooden handrail. The two parts of the face of the house facing the street, on first-floor level, were covered with 2mmthick steel sheet, consisting of unpainted CQ. These sheets have now rusted to a dark, reddish-brown colour.

S TE E L AWA R DS 2 015 W I N N E R S

RESIDENTIAL CATEGORY COMMENDATION:

The judges noted that, after the significant contribution that Hennie de Clercq made to the hot rolled steelwork and LSFB industries during his tenure as SAISC executive director, it came as no surprise that he combined both mediums in an amazing house for his wife Helena and himself.

Crossing Bridges

Whether it’s intricate community bridges, massive mining headgear, revolutionary light steel frame restaurants, innovative multistorey modular technology, state-of-the-art computerised fabrication technology, expert international export strategy or training industry personnel in the latest techniques of the steel construction trade, the Southern African Steel Construction Industry can be proud of the bridges it has crossed to become a world class industry.

SOUTHERN AFRICAN INSTITUTE OF

STEEL CONSTRUCTION

Steel leaves a legacy.

Southern African Institute of Steel Construction Tel: +27 11 726 6111 Email: info@saisc.co.za www.saisc.co.za

SAISC 210x145 ad.indd 1

2/17/15 3:02 PM

S TE E L AWA R DS 2 015 W I N N E R S WINNER MINING AND INDUSTRIAL CATEGORY: MEDUPI POWER STATION - AIR COOLED CONDENSER In 2007, GEA approached A.Leita and Kentz to submit a bid for the Medupi air cooling structures, some 26,000 tons of steel.

A.Leita teamed up with Cadcon and Boksan Projects and formed the ABC Joint Venture, with A.Leita leading the fabrication team and Kentz doing the on-site work.

“And what a great business decision that was for all the players,” the judges remarked. “They are one of few power station contractors who can proudly boast of being on time and having produced a virtually problem-free, high-quality product.”

According to the judges, when one visits the site, because of the enormous boiler houses which stand close to the air cooling units, one is surprised to learn that each unit has more than 4,000 tons of steelwork. “To grasp just how big a project the air cooling actually is, it was necessary for us to drill down into what makes these units tick,” they explained.

50

There is an air cooling unit for each of the six boilers; the radiators sit on a structural steel support structure; floor beams are covered with 4mm floor plates; an A-frame structure is fabricated out of heavy H-beams; and the fan bridges span between the main girders.

“Just try to picture the girders, 27 metre span, 7.2 metres deep with a mass of 30 tons each! The units each have a footprint covering 112metres x 108metres – almost the size of two adjacent soccer fields. There are, in addition, secondary structures such as staircases, cat-ladders, ESD supports, wind walls at ground level, and control rooms,” the judges elaborated, noting that detailing was done by the JV using Tekla software.

The elements, the environment, future water cleaning requirements, inaccessibility and long lifespan requirements of the client (Eskom) led to the decision to hot dip galvanize the steelwork. The JV was helped to achieve their delivery commitments by a record throughput by the then Robor Galvanizers (now known by their original name, Monoweld Galvanizers).

The judges said that even though this is a mega project, it is not something new for the South African structural steel industry.

SEPTEMBER 2015

S TE E L AWA R DS 2 015 W I N N E R S Here is why this project stands out and is so deserving of first place in this category: • The Medupi site has been beset with labour difficulties, and despite all the troubled times on site, the GEA/Kentz/ABC JV team maintained good relationships.

• Given a chance, South African contractors can and will ramp up to deal with any size of project.

• South Africa has the facilities, equipment, skills, labour and technology to fabricate and manage such projects.

• The welding requirements for those massive girders and A-frames, all to AWS D 1.1 can be achieved by following the recommendations of AWS and by training the welders to meet such requirements.

The judges said this entire project team, which so successfully completed this project, ought to be complimented. “The logistics of designing, detailing, procuring, fabricating, galvanizing, assembling, quality controlling and delivering 26,000 tons of steel was a significant challenge. And to cap it all, to have completed on time was an outstanding achievement and thoroughly deserving of the number one spot in the Mining and Industrial Category.”

PROJECT TEAM CLIENT: Eskom TURBINE CONTRACTOR: Alstom AIR COOLING MAIN CONTRACTOR, STRUCTURAL ENGINEERS, QUANTITY SURVEYOR AND PROJECT MANAGERS: GEA Air Cooled Systems MAIN CONTRACTOR, STEEL ERECTOR AND CLADDING ERECTOR: Kentz Engineers and Contractors STEELWORK FABRICATORS: A. Leita Steel Construction, Boksan Projects, Cadcon STRUCTURAL STEEL DETAILER/DETAILING COMPANY: Mondo Cané Structural Steel Detailers GALVANIZER: Robor Galvanizers

SEPTEMBER 2015

51

S TE E L AWA R DS 2 015 W I N N E R S WINNER FACTORY AND WAREHOUSE CATEGORY: VALUE LOGISTICS DISTRIBUTION CENTRE The judges said of Value Logistics’ new distribution centre in Kraaifontein, Western Cape that “this is one of those model projects in which, from start to finish, one can see that the structure was well-designed, that the team worked closely to make the programme work, and that the architects could fulfil their vision of a highly aesthetically pleasing office facility.”

They added: “In order for Value to offer its wide range of logistical services, it must have distribution centres that allow for the offload, sort, store, reload and delivery of any product imaginable, from the biggest to the smallest quantities, both domestically and internationally. The new facility fulfils these requirements ingeniously.”

52

The installation consists of two warehouses, one for Value Logistics (about 13,000m²) and one for Freightpak (about 7,000m²), as well as support facilities such as wash bay and vehicle inspection, despatch, refuelling, gatehouse and canopies to many of the structures.

As one would expect, these warehouses are massive – with columns spaced far apart, with the double pitched roof (the Klip-Lok roof sheeting was of course rolled in long lengths on site) supported on light transverse roof trusses, which in turn are carried by long span longitudinal lattice girders between the columns. In this instance, the lower sections of the columns are made using tilt up concrete columns. “The substantial clear height inside the buildings takes you by surprise, until you notice the very high racking storage areas.”

SEPTEMBER 2015

S TE E L AWA R DS 2 015 W I N N E R S

“Of course such buildings, by their very nature, need height for storage and for handling operational vehicles,” the judges said.

“And then there is a little architectural gem tucked away on this otherwise very functional and industrial site,” the judges continued, “We have come to expect a two-storey rectangular box that houses the offices for such a project. Definitely not so in this case! This beautifully detailed structure with exposed steel extending to the glass-fronted reception area, with ponds and aesthetic décor, transforms this good industrial project into an absolute winner – truly deserving of B&T Steel’s Factory and Warehouse Category for excellence in the use of steel,” they concluded.

PROJECT TEAM CLIENT: Loudon Property Investments ARCHITECT: Loudon Perry Anderson Architects STRUCTURAL ENGINEER: Sutherland Structural Engineers QUANTITY SURVEYOR: JMHT Quantity Surveyors MAIN CONTRACTOR: Group Five Coastal STEELWORK CONTRACTOR, DETAILERS: Union Structural Engineering Works CLADDING CONTRACTOR: Scheltema Roofing PAINTER: Nu Nation Protective Coatings

CALL 0861 727 663 TO BOOK YOUR SPACE IN

SEPTEMBER 2015

53

S TE E L AWA R DS 2 015 W I N N E R S WINNER ARCHITECTURAL CATEGORY: MULTICHOICE CITY Multichoice City is a large expansion to the east of the current Multichoice/MNET campus on the eastern side of Bram Fischer Drive in Randburg. The primary purpose of the building is for offices and a call centre, but the building has been developed as the flagship to the current campus. The judges said that the use of steel played a vital role in emphasizing the filigree detail that completes the building.

A visitor entering the building is immediately greeted by a grand volumetric atrium space with a wonderfully elegant tubular strutted arch structure supporting air-inflated ETFE cushion cladding. The strutted arch spans 24 metres and its

54

form is ideal for resisting the more dominant uplift wind forces of such a structure, whilst being quite slender in form as a result of the very light (in mass) ETFE cushions. The atrium space is further complemented by beautifully detailed structural steel staircases.

The front of the building facing west on Bram Fischer Drive has a very large cantilever ‘peak cap’ roof that cantilevers out towards the street. This roof has been sculpted to ensure that form follows function, with a very elegant narrow leading edge.

Structurally, the roof comprises fabricated box girders tapered in section, cantilevering generally 12 metres (maximum cantilever being 13.5 metres). The closed box form is further stabilized by a tubular bracing network ensuring, despite the large cantilever, that the structure remains stable. The back edge of the roof allows free flow of wind under it to ensure wind uplift forces are minimized.

SEPTEMBER 2015

S TE E L AWA R DS 2 015 W I N N E R S Also facing Bram Fischer Drive is a ‘jelly bean’ shaped portion of the building, clad in active glass louvres. These open and close automatically to shade the interior from the late afternoon sun, whilst leaving uninterrupted views for most of the day. Tubular steel arms cantilever out from the slab behind to support a curvilinear tubular member that supports the glass louvres and mechanical actuators. The project team said the early involvement of the two steelwork contractors in the design process played a major role in achieving the beautiful end result.

The building has achieved a Four Star Design Rating from the Green Building Council SA and is currently being assessed for the ‘as built’ rating.

The judges said the mechanized glass louvres, ETFE cushion roof and dramatic cantilever ‘peak cap’ roof, along with all the other filigree steelwork, go a long way in achieving the architect’s vision for a crisp, modern and elegant office building showcasing modern technologies synonymous with Multichoice’s business strategy. “A practical and beautiful structure thoroughly deserving this award,” they concluded.

PROJECT TEAM CLIENT: Multichoice - Multichoice Support Service ARCHITECT: GLH and Associates Architects STRUCTURAL ENGINEER: Pure Consulting QUANTITY SURVEYOR: BTK Pretoria Inc PROJECT MANAGER: M Studio Consulting MAIN CONTRACTOR: Group Five STEELWORK CONTRACTOR, DETAILING COMPANY: Tass Engineering, Nancy Engineering CLADDING SUPPLIER: Global Roofing Solutions CLADDING ERECTOR: Cladco Projects ETFE CUSHION ROOF DESIGN AND SUPPLIER: Novum Holdings LLC South Africa

SEPTEMBER 2015

55

S TE E L AWA R DS 2 015 W I N N E R S WINNER CLADDING CATEGORY: “PEAK CAP” AT MULTICHOICE CITY Passed by thousands of commuters daily, the underslung cladding to the peak cap feature on the new Multichoice City, which won the inaugural Global Roofing Solutions Cladding Category at Steel Awards 2015, must be one of the most visible cladding solutions in South Africa. Multichoice City also won the Architectural category.

The judges said this project was a clear winner. “Hanging underslung cladding is a process not for the faint-hearted. It is exceptionally difficult to do well, especially with the hidden fixing type of cladding used on this project,” they continued.

The cladding is to a 12-metre cantilever which follows its structural shape requirements, tapering from width at the support end to a narrow tip. The project team said that the installation procedure was a challenge due to the length of the sheet and the fact that the underslung design meant few or no blemishes. “The curved end detail succeeds in making the extremely narrow tip edge of the cantilever the important feature it has become in the finishing of this daring architecture,” they said.

Specialized flashings were incorporated on the edges of the canopy between the roof and the underslung sheets. These flashings had a unique individual radius due to the complex design. Klip-Lok 700 was used on the roof, which was suited to the low pitch of the roof.

The judges noted that this new category was the brainchild of Dennis White, the director of the Southern African Metal Cladding and Roofing Association (SAMCRA), and paid tribute to him and Global Roofing Solutions, a founding member of the Association and sponsor of this category.

56

PROJECT TEAM CLIENT: Multichoice - Multichoice Support Service ARCHITECT: GLH and Associates Architects STRUCTURAL ENGINEER: Pure Consulting QUANTITY SURVEYOR: BTK Pretoria Inc PROJECT MANAGER: M Studio Consulting MAIN CONTRACTOR: Group Five STEELWORK CONTRACTOR, DETAILING COMPANY: Tass Engineering (Pty) Ltd CLADDING SUPPLIER: Global Roofing Solutions CLADDING ERECTOR: Cladco Projects

SEPTEMBER 2015

S TE E L AWA R DS 2 015 W I N N E R S The stalls have been reconstructed as moveable timber units, such that this area could be vacated temporarily for larger events. It was therefore important that the 23m-wide central area be column-free. A central driving force in the overall design was the need to visually connect the spaces on the various levels. Structural steel was the ideal material to achieve this.

WINNER RETAIL CATEGORY: THE WATERSHED AT THE V&A WATERFRONT “The Watershed” is the name given to the re-developed Blue Shed, situated along the pedestrian route from the Victoria Wharf Mall to the Two Oceans Aquarium at the V&A Waterfront. Previously, part of this historic warehouse was occupied by a craft market, with the remainder having long been vacant and in poor condition.

“This project displayed innovation and excellence in the use of structural steel,” the judges remarked. The Watershed project was born out of an urban strategy to improve and upgrade the pedestrian experience, whilst also seeking to provide a socalled Innovation Hub and exhibition space. There was also a desire to reinstate and enhance the Blue Shed craft market. To achieve this, the alterations involved opening the gable ends of the building, and re-routing the pedestrians through the warehouse to create an inside-out/outside-in space, with two new floor levels to house the Innovation Hub, exhibition hall and retail tenancies.

The ground floor space has been converted into an ‘undercover street,’ with the upper floors flying over.

SEPTEMBER 2015

From an energy and sustainability point of view, translucent skylights, high-performance glazing, roof insulation in enclosed areas, ridge ventilators and the open gable ends were used to passively provide comfortable internal conditions. Airconditioning to selected offices and retail spaces were linked to a centralized ‘chiller,’ which also serves the adjacent building.

The re-use and conversion of the existing shed helped to reduce wastage, and the multi-use planning allows efficient and flexible use of the available bulk.

“All-in-all, the architectural ingenuity employed in creating inter-connected and interesting spaces with detail-intensive design has led to the development of a world-class facility using an existing building,” the judges concluded.

PROJECT TEAM CLIENT: V&A Waterfront Holdings (Pty) Ltd ARCHITECT: Wolff Architects (Pty) Ltd STRUCTURAL ENGINEER: LH Consulting Engineers (Pty) Ltd QUANTITY SURVEYOR: Pentad Quantity Surveyors (Pty) Ltd MAIN CONTRACTOR: WBHO Construction (Pty) Ltd STEELWORK CONTRACTOR: Mazor Steel (Pty) Ltd, Kilpin Engineering (Pty) Ltd, Olympic Steel CLADDING CONTRACTOR: GSM Roofing GLAZING (STEEL WINDOWS): Metal Windows

57

M A R K E TI N G CO M M U N I C ATI O N

Can you trust what you read?

Nowadays, especially at a social level, we are subjected to numerous instant messaging platforms being used to push not only the news, but also marketing information – and even serious technical content. Somewhere inside these issues lie golden opportunities for the effective communicator with the mind of a fox.

Article by Gareth Griffiths, technical writer, professional photographer and owner of the media service agency ENERGY|MC.

TO ADVERTISE OR NOT Global and national economic times are tough. Humankind faces some of the toughest macro-environmental and social challenges ever. These include the future of our economy as we know it, growing poverty, and the huge challenge of climate change caused by the impact of our lifestyle on the environment.

Amidst the literal barrage of information streams coming our way, many advertisers are cutting budgets – an easy target during times of recession. Clever companies, however, question whether they are ready to walk away from the brand recognition they have established within the market by cancelling marketing communications going forward. After all, advertising and other promotions such as PR are strategic endeavours.

58

Brands are not built overnight, but rather along the lines of a consistent long-term campaign, supported of course by your performance as manufacturer, supplier, consultant, contractor or other professional.

CHOOSE THE RIGHT MEDIUM More than 50% of commercial and industrial clients still use print media publications as their informative source of reference. Of these readers, a large majority are in senior decision making positions – not having the time to learn and adapt to the messages of the social media on the web. Readers such as these are looking for well written, informative content, supported by logical arguments.

SEPTEMBER 2015

Electronic content is not always the ideal medium for this, especially with the evolution of smartphone platforms.

How would you choose to address your serious technical message to someone reading the Twitter feed on their smartphone while on the airport bus?

“A man who stops advertising to save money is like a man who stops a clock to save time.” – Henry Ford A CREDIBLE MESSAGE This brings up the main point – how reliable is the information we receive? In current times, content is king.

For the firm of architects wanting to communicate their narrative of success, there is a desperate need for plain English: Well written content backed with photography that conveys a story. The same applies to a system or material supplier wanting his product or service offering to be specified on the drawing board or bill of quantities. Effective communication with your desired audience depends on speaking to them in a language that: • Is of interest to them, • Makes sense, and • Is unambiguous and easily actionable.

Looking through some marketplace advertisements, it is often hard to see the point. Some of these ads are prepared in graphics studios that know little about the end user and nothing about the technology. They are pleasant eye candy, but that's all.

Many companies put serious, well written content at the bottom of the pile in preparing their corporate and marketing communications. They seem to fall into the well worn trap of underestimating their audience.

They need to bear in mind that readers expect a magazine to deliver content that provides relevance and solutions to problems.

THE ART OF GOOD EDITORIAL How is this best done? Many publications, both online and in print, offer opportunities for enhanced messaging via their editorial pages. Editorial is the news line of the magazine and readers expect useful information with relevance to their line of business. Editorial cannot simply be advertising that has been washed clean of slogans and logos. It needs to describe the importance of the subject generically to the interested person and then demonstrate impartially why your solution as a product, contractor, project manager, consultant or other service provider meets the needs of the client.

Simply put, this means plain English backed with decent photography, not merely a logo with a few images taken haphazardly with a smartphone.

For more information, email Gareth Griffiths at gareth.energymc@gmail.com, call him on 072 905 0252, or visit www.energymc.co.za or photography website www.professionalphotoshoots.co.za.

SEPTEMBER 2015

10 Thora Cresent, Wynberg, Sandton, Johannesburg 011 262 4151 charles@frontier-electronics.co.za brinnosa.co.za facebook.com/brinnoafrica

TH ATC H ROO F I N G

Thatch: Leaks caused by incorrect maintenance The case study of this 212m2 house, including the overhang, is a good example of why only a reputable thatch contractor should be appointed to install and maintain your valued thatch roof.

Case study provided by TASA (the Thatchers Association of SA), with input by Dawid Pretorius from Con-Thatch.

Photographs courtesy of Con-Thatch.

THE PROBLEMS Big hail stones can cause thatch to break, leaving indents. In this case, following a severe hail storm, the homeowner reported thatch damage to his insurance company. The insurance company appointed a thatch contractor (not named in this article) to brush and comb the roof. However, after the brush and comb process was complete, the homeowner again contacted the insurance company with complaints of widespread leaks after it had rained.

After the indents had been removed by the brushing and combing process, there should have been sufficient remaining thatch coverage over the sways. This time, the insurer appointed TASA member Con-Thatch to evaluate the situation and determine whether the thickness of the thatch remained adequate. Unfortunately the professional assessment by Con-Thatch showed that the roof was well below the accepted minimum average thickness of 150mm.

60

SEPTEMBER 2015

TH ATC H ROO F I N G

With a newly thatched roof, the horizontal sways (i.e. 3,15mm wire or cape reed in bundles of at least 10mm) are actually securing the thatching twine, and is covered with thatching grass at least 75mm thick, so that you see a smooth finish with no horizontal lines visible.

Thatch compaction is the tension of the twine being applied on the thatch between the sway on top and the batten below.

Compaction is determined by the binding tension of the (in this case) sisal twine. As there were no horizontal wires (sways) visible on the surface of the roof, Con-Thatch tested the compaction of the thatch from the inside by pulling the twine.

It was an unpleasant surprise for Con-Thatch to find that, in five different sections of the house, the twine was broken and pieces could be pulled out. It was not possible to determine with certainty whether the twine had been cut or broken during the brushing and combing process, or if this was natural deterioration.

Regardless of the cause, the broken twine meant that all the compaction was gone, and the thatch was literally just laying loose on the roof, resulting in parts of the thatch not being secure at all. In all probability, this was the main cause of the leaks.

Although one can easily determine the compaction of the thatch by pulling the twine, there is also a tool available for a more accurate measurement. Note:The compaction should be a minimum of 8kg. If the roof is loosely thatched and one pulls the twine on the inside, a noticeable indent in the thatch will appear on the outside.

THE SOLUTION Not knowing where the sways are, it is not recommended to try and ‘fix’ this situation. Firstly, it is extremely difficult to identify only certain problem spots and then remove and re-thatch only those areas. Moreover, because the thatching process starts from the bottom upwards, it is simply not a good idea to only re-thatch damaged sections or patches here and there.

Instead, the entire roof should be re-thatched (referred to as overlay) correctly. The second layer must be secured through the existing thatch onto the laths on the inside. Please note that the existing pole construction was adequate to carry an additional layer of thatch.

On the two verandas, the existing thatch layer needs to be completely removed, because a second layer on top of the existing layer will make the overall thickness of the thatch higher than the window ledge.

CONCLUSION Thatch installation and maintenance problems can be avoided by appointing a reputable, experienced thatch contractor that will follow industry standards so that you can enjoy your thatch roof to the fullest extent. TASA is available to assist with thatch inquiries and can help find a reliable thatch contractor in your area.

FOR MORE INFORMATION: Con-Thatch (TASA member) Dawid Pretorius Email: info@con-thatch.co.za Website: www.con-thatch.co.za TASA Elzabie Meintjes Email: admin@sa-thatchers.co.za Website: www.sa-thatchers.co.za

SEPTEMBER 2015

61

TH ATC H ROO F I N G

Thatch needs more than just a comb-over It is essential to service a thatch roof with proper brushing and combing. But unless it's correctly done, the cover above the sway could get reduced and adversely impact the lifespan of the thatch. Only let a qualified thatcher - with expert knowledge of the technical detail of a thatch roof - comb your thatch.

Article by: John Smith, owner of Biggarsberg Thatchers (TASA Member) Photographs: Courtesy of Biggarsberg Thatchers

The right side of this roof has been serviced – note the raised thatch.

TASA RECOMMENDATION TASA, the Thatcher's Association of South Africa, strongly recommends that only experienced thatch contractors be appointed to install and service thatch roofs. The combing process must be well supervised, since inexperienced or uninformed thatchers could take shortcuts that could ultimately destroy the roof and result in insurance claims being rejected.

Pulling down of thatch layers.

62

Tightening of twine after pulling down the outer layer of bundles.

SEPTEMBER 2015

TH ATC H ROO F I N G

The very first course of action to take is to inspect the general length of the thatch or reed. If found long enough, the thatch layers can be pulled down. This aspect of a thatch roof is critical, because the length of the stem below the twine actually has a direct bearing on the lifespan of the roof.

Next, the binding twine must be tightened on the underside of the roof, and only then can the combing process begin.

NEW ROOF INSTALLATIONS It is important to achieve optimal functional thickness: The cover over the sway, or the functional thickness of the thatch, should never measure less than 70mm. The overall thickness of the thatch layer must total no less than 175mm.

This photo shows short stem placing below the twine, which is incorrect, and can therefore result in a shortened lifespan.

This photo shows good stem placing below the twine, which is correct at 250mm/300mm, and will therefore result in a longer lifespan.

1

2

3

4

This image shows the thatch bundles over the laths.The bundle length should span at least 3 gaps, meaning the tip must reach the 4th lath.

FOR MORE INFORMATION: Section through newly installed thatch layer.

The optimal length to ensure maximum roof life is 250mm to 300mm. This efficiency should not only be carefully controlled during the thatch installation, but also be maintained. Care should be taken not to exceed 300mm in common thatching grass, as it can be prone to wind damage.

SEPTEMBER 2015

Biggarsberg Thatchers John Smith Email: thatchers@thatcher.co.za Website: www.thatcher.co.za TASA Elzabie Meintjes Email: admin@sa-thatchers.co.za Website: www.sa-thatchers.co.za

63

S TE E L I N D U S TRY

The State of Steel:

Comment from Paolo Trinchero - SAISC Executive Director The Southern African Institute of Steel Construction (SAISC) is concerned about the immediate future of the local steel industry. Here the SAISC executive director, Paolo Trinchero, explains why.

“On average, South Africa produces about seven million tons of steel per year, of which about five million tons is locally consumed. I think this year is going to be one of the worst in the steel industry’s history, with consumption at below 4.5 million tons,” Trinchero says.

He adds that China exported 100 million tons of steel last year and has the capacity to produce over 750 million tons. “It is not uncommon for imported Chinese fabrications to land on our shores at a lower cost than that of raw steel, and there is a very real possibility that practices such as these could have a catastrophic effect – not only on the South African industry, but on the global steel industry.”

Turning to local issues, Trinchero says that each unit of the Medupi and Kusile power stations required about 20,000 tons of steel per support structure. “In comparison, one large shopping mall such as the Mall of Africa needed about 1,000 tons of structural steel for its roof. So, when we stop building power stations, we will have to build twenty large shopping centres to compensate for the lost work from each unit. This is currently a very real challenge,” he continues.

The structural steelwork for the first four units of Medupi and Kusile – eight units in total – was all fabricated in South Africa using locally sourced steel. The last four units however, two from each power station, are being supplied from Germany, Saudi Arabia and Vietnam.

“It has been said that South African contractors were slowing things down but, in fact, all of the locally ordered structural steel is sitting in the ‘veld’ out there. Steel was never on the critical path for these power stations and, if we hadn’t procured the last third of the work from overseas, we could have had our own fabricators working right now, producing the steel for the last four boilers. Instead, most South African structural steel fabricators are having to retrench staff,” Trinchero says.

“That is a scary statistic! It is hard to imagine one of South Africa’s largest fabrication facilities running at 2% capacity.

“The only opportunity left open to them was to export. There are no more big projects on the South African horizon, and the reality is they - and others - will be retrenching a lot of workers unless we can secure overseas work.

“It is a tragedy that our local industry is being decimated, and it is surely in our interests to support and protect it through incentives. We are working closely with government along the lines of the following ‘wish list’ that I have submitted: • Investor confidence is key, and government policy needs to create confidence.

• Release work into the economy. Prioritize and implement parts of the NDP that will have the biggest impact.

• Encourage localization. While this is being done by the DTI already, it needs to be embraced by SOEs and large local businesses.

• Help team SA to generate a substantial export revenue stream by looking for a wide range of measures such as energy inputs, logistics, etc.

• Ensure the protection of the entire industry from unfair competition.

“It’s tough times at the moment for our industry, but we remain hopeful,” Trinchero concluded.

For more information, email info@saisc.co.za, phone (011) 726 6111, or visit the SAISC website at www.saisc.co.za.

“The current difficulties being faced by the South African steel industry cannot be over emphasized,” he warned, reminding us of two key problems: The total lack of project work and the unrestricted access China has to South African markets.

Trinchero says the biggest challenge to the local fabricators is order book. “Take one of the leading fabricators in South Africa with capacities of 30,000 tons per year. Its current order book is 600 tons, we are told.”

64

SEPTEMBER 2015

S TE

ST CER

TI

FI TE

EM

IS

ON

CA

SI

I

IO

AT

E

EM

SS

NS

TEST CERT

IF

IC