perspective BUILDING SCIENCE
SPRING 2022
NORTHERN LIGHTS RENEWED:
PUBLICATIONS MAIL AGREEMENT #40934510
Replacing the building envelope on an active treatment hospital
Technical challenges of Passive House Certification and why the standard is here to stay How to prevent common basement leaks: Tips and recommendations for property owners AN ALBERTA BUILDING ENVELOPE COUNCIL NORTH & SOUTH CHAPTERS PUBLICATION
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IN THIS ISSUE www.delcommunications.com PRESIDENT / PUBLISHER David Langstaff MANAGING EDITORS Cindy Chan cindy@delcommunications.com Shayna Wiwierski shayna@delcommunications.com
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Message from the ABEC North President, Amir Hassan
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Message from the ABEC South President, Fred Edwards
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ABEC North and South Board of Directors
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Rising From the Ashes
12
Northern Lights Renewed
SALES MANAGER Dayna Oulion dayna@delcommunications.com
16 Technical Challenges of Passive House Certification and Why the Standard is Here to Stay
SALES REPRESENTATIVES Brent Astrope | Corey Frazer | Colin James Ross James | Mic Paterson
22 Case Study: Blistering in Linoleum Flooring Installed Over a Concrete Slab-On-Grade
PRODUCTION SERVICES S.G. Bennett Marketing Services
26 Local Legends: Alan Dalgliesh Honoured for Contributions to Building Science
CREATIVE DIRECTOR / DESIGN Kathleen Cable COVER PHOTO COURTESY OF Rockliff Pierzchajlo Kroman Architects, Building Science Engineering Ltd., and Dobie Photography PUBLICATION COMMITTEE Bob Passmore | Brian Shedden | Ed Bushnell Fred Edwards | Kevin McCunn | Jamie Murphy © 2022 DEL Communications Inc. – All rights reserved. Contents may not be reproducedby any means, in whole or in part, without the prior written permission of the publisher. ABEC does not specifically endorse the editorial, products or services contained within this magazine. These products and services are presented here as an indication of the various possibilities in the Marketplace. ABEC wishes to advise the reader that sound Building Science Practices should be applied to any and all product or service selections. ABEC does not make or imply any warranties as to the suitability of any of these products or services for any specific situation. Furthermore, the opinions expressed in this magazine’s editorial content may not necessarily reflect the opinions of ABEC.” While every effort has been made to ensure the accuracy of the information contained herein and the reliability of the source, the publisher in no way guarantees nor warrantsthe informationand is not responsiblefor errors, omissions or statements made by advertisers. Opinions and recommendations made by contributors or advertisers are not necessarily those of the publisher, its directors, officers or employees. Publications Mail Agreement #40934510 Return undeliverable Canadian addresses to: DEL Communications Inc. Suite 300, 6 Roslyn Road, Winnipeg, Manitoba R3L 0G5 Email: david@delcommunications.com PRINTED IN CANADA | 04/2022
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28
Floodplains of Rivers
30 How to Prevent Common Basement Leaks: Tips and Recommendations for Property Owners 32
Industry Expert Q&A: Brian Shedden
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Designing for Floods
41
Crossword
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Index to Advertisers
Why your IIBEC chapter needs a magazine:
• Revenue generator • Member engagement • Member attraction • Image builder To find out more on how your chapter can have a magazine at no cost contact: Gladwyn Nickel DEL Communications Inc. 1-877-878-4077 gladwyn@mts.net
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Amir Hassan
Message from the ABEC North President
President, ABEC (North)
F
inally, after two long years, we see pressures on the health-care system noticeably subsiding and governments across the country are working hard towards implementing progressive steps to remove public health measures. We’re all hopeful these latest efforts will bolster our economy and lead to renewed community events and activities. We hope to go back soon to in-person lunch-and-learn sessions and social gatherings. Our next in-person luncheon will be on April 26, 2022, and next joint golf event with CSC on June 30, 2022. Propelled with the positive feedback of the last two issues, we are excited to present the third issue of Building Science Perspective. This rich publication is made possible by the hard work and commitment of our passionate and knowledgeable technical committee from ABEC North and South. We have another ongoing epidemic with the quality of building enclosures. Many leaky buildings and underperforming envelope systems continue to be constructed across Alberta. One way to avoid many of the problems continuing to occur is engage a Building Envelope Commissioning Agent (BECxA). Introducing commissioning at the predesign stage of a project has proven to have favourable payback to many owners. The greatest benefit is that the building systems are installed and operated properly, according to the design intent before the building is occupied. Consequently, warranty service calls to fix problems in occupied areas are greatly reduced. The commissioning process is a separate series of activities led by BECxA, and requires participation from the owner’s staff, design team, and contractors. Commissioning starts before the design phase and continues until after building occupancy. Design phase commissioning activities involve review of the design intent manual prepared by the design team, and review of the design drawings at all phases. This independent review ensures that the design intent – which often gets lost in the design process – is incorporated in the construction documents and contains adequate information to allow functional performance testing of building systems at the end of the construction administration phase. The construction administration phase contains the most intensive commissioning activities. Using the design documents and the shop drawings, BECxA prepares specific pre-functional checklists to aid the contractors in the start-up process. Not only must individual components and sequences operate properly, but also all independent systems must operate in concert as a functioning whole. This interoperability is verified through carefully developed functional performance test procedures for building envelope systems. Using the basis of design manual and the contract documents, expectations of system performance are established and conveyed to the contractors in a clear pass/fail format. After all, commissioning is not a milestone; it is a quality-focused process, enhancing the delivery of all energy and resource using systems. ABECN is a non-profit society dedicated to encouraging the pursuit of excellence in the design, construction, and performance of building enclosures and to advancing educational and technical standards within the building envelope industry. This council welcomes anyone interested in the evolving field of building envelope. To know more about us, visit our website at www.ABECNorth.org and follow us on ABECN LinkedIn Page. Happy reading!
Amir Hassan, M.Sc., P.E., P.Eng. President, Alberta Building Envelope Council (North)
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experience | practicality | service ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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Fred Edwards
Message from the ABEC South President
President, ABEC (South)
B
uilding Science Perspectiveis gaining momentum. Your Alberta BECs are excited about the third installment of this local, all-things-building-science magazine. In this issue, we have made an effort to expand our horizons and have added manufacturers and other external perspectives to the content.
Spring 2022 also saw the lifting of most of the provincial health restrictions in Alberta. That means the return of the ABEC South monthly luncheons. Our luncheons are held the fourth Thursday of every month between January to May and September to November at The Winston. Each month, our luncheons feature topics and speakers from our specific industry. At $40 (members price) for a plated lunch and sponsored bar, you will be hard-pressed to find a networking and professional development opportunity offering better value. We are also looking forward to hosting our annual golf tournament in June, so we hope to see you at Elbow Springs Golf Club. An event calendar is posted beside this column for reference and to book off dates for this event and our luncheons in your calendar. Energy efficiency remains an important topic in our industry and the driver of most building envelope policy decisions. Jurisdictions such as B.C. who have legislated a step code are now requiring whole building air tightness testing as a commissioning activity to demonstrate that a new project has a chance of meeting its energy efficiency goals. In expectation of air tightness testing becoming more prevalent in our market, ABEC South elected to partner with Red River College Polytechnic from Winnipeg and bring their air tightness testing course to Calgary. Two courses will be held from March 25 to 29 at the ARCA building in Northeast Calgary. Both courses are full but given the demand, we will look into options for additional courses in the future. The ABEC South Executive has also received requests from our members to look into appropriate ways that ABEC South can support the promotion of building science in Alberta. In response, Kris Wall, Mike Dietrich, and Kevin Brown have agreed to form a sub-committee to look into available opportunities. I look forward to reporting to the members on the outcome of this initiative in future reports. This year will also see the return of the Canadian Conference on Building Science and Technology, hosted by OBEC in Toronto October 2022. A number of ABEC North and South members will be attending and presenting at the conference and we wish them the best. We encourage our readers to look into this conference, and consider attending. Thanks for reading and we welcome any feedback you have on the content of this magazine or suggested topics for inclusion at lunch seminars.
Fred Edwards, P. Eng. President, Alberta Building Envelope Council (South)
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CALENDAR OF May Luncheon
June 22
ABEC South Golf Tournament
June 30
ABEC North and CSC Edmonton Chapter Joint Golf Tournament
September 28
ABEC South AGM and September Luncheon
October 26
October Luncheon
November 23
November Luncheon
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May 25
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EVENTS
ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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North Board of Directors
South Board of Directors
AMIR HASSAN, MSc, PE, P. Eng. – President
FRED EDWARDS, P. Eng. – President
RICHARD LUCID, CTR – Membership
KRIS WALL, P. Eng. – Past President
BILLY HUET, P. Eng. – Education
ANTON VLOOSWYK, P. Eng. – Treasurer/NBEC Rep
GARRATT GRENIER, RRO, CTR – Programming
BOB PASSMORE, Architect – Secretary
RYAN ASSELSTINE – Treasurer
DENNIS LOOTEN, Life Member CSC, FCSC, B.Sc. – Education
KEVIN MCCUNN, P. Eng. – Technical Reviewer
MAIREAD WALSH, P.L. (Eng.), LEED AP – Membership
BRIAN SHEDDEN, BSS®, Q.Adj. – Director
GREG MARTINEAU – Programming
ANDY DOLAN – Director
MIKE DIETRICH, MASc. – Director
JOE MIS – Director
RANDY KIEZ, CET – Director
JAMIE MURPHY, RET, P.L.(Eng), CCCA, LEED® AP – Director
SATHYA RAMACHANDRAN, B. Arch. – Director MARTY DEEMTER, P. Eng. – Director ED BUSHNELL – Director JON SOLLARD, P. Eng., RRC, RRO – Director
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RISING FROM THE ASHES
I
By Brian Shedden. BSS®, Principal, Entuitive
f you think that building sustainably is expensive now, just wait until you don’t build sustainably. Cast your mind back to May 2016: do you remember what happened?
Dateline Fort McMurray. The costliest insured loss in Canadian history was the result of the wildfire that literally burned many parts of the town right to the ground. Remember those scenes on the news? Tremendous walls of flames that actually jumped rivers forcing the evacuation of the entire population of 67,000 with very little notice. Did you know that here in 2022, they are still rebuilding from that devastation? Now, what does this have to do with building science? Well, think about this for a moment: •F ort McMurray is located within the boreal forest, a forest that occupies over 50 per cent of the Canadian land mass and runs from coast to coast. •F orest fires have occurred since the beginning of time and are usually ignited by natural means such as lightning. •T he term “wildfire”, a relatively recent addition to the Lexicon, has been tagged to those fires that speedily encroach on cities or towns, raising alarms and triggering emergency response plans. •M ost of the losses were to single-family homes built under Part 9 of the Building Code. •M ost of the homes included wood framing, vinyl siding, asphalt shingles and vinyl framed windows, all of which offer no resistance to fire. As building science specialists and building envelope consultants, each of these points above are relevant to our area
of practice. Now, we could do the minimum and simply design to Code, but remember, Code is not the gold standard; it is essentially the worst thing you are permitted to build, legally. It is imperative that we consider all of the factors that may affect our projects over their normal service life. For example, if you were building in a coastal setting, failing to factor in rising sea levels would be a recipe for disaster. Similarly, if you are building in the middle of one of the world’s largest forests, combustibility or fire resistance demand that we design in a manner that acknowledges the real threat potentials, and a design that does will be one of the biggest sustainability initiatives you could incorporate into the project. Let’s look at the cost side of this equation. In one 214-unit condominium complex that was devasted by the fire, the costs to rebuild far outstripped the replacement value covered under insurance, leaving many of the unit owners not only homeless as a result of the fire, but continually homeless, as in being unable to cover the additional costs required to rebuild. As you know, here in Alberta, our insurance rates have sky-rocketed in recent years, due in no small measure to the enormous losses sustained by the insurance companies in Fort Mac. And those rates will continue to be high until we take measures to mitigate losses in the future. So, in the big scheme of things, the premiums associated with utilizing fire rated cladding, metal roofing and metal framed windows and doors are really peanuts compared to real and present downside of not having designed and built in accordance with the demands of the environment in which we are working. If your client fails to understand the importance of this, you have a choice to make. You can either be part of the problem or part of the solution. I think that’s a pretty easy choice. n ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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Before. After.
NORTHERN LIGHTS RENEWED Replacing the building envelope on an active treatment hospital By Jan Pierzchajlo, Principal, RPK Architects Ltd. With co-contributors Allan Colpitts, Principal, ACI Architecture (former Senior Project Manager, Alberta Infrastructure), and Chris Makepeace, Building Science Engineering Ltd. This article provides a case study of the replacement of the building envelope of the Northern Lights Regional Health Centre in Fort McMurray, Alberta.
Fire of 2016 threatens the hospital. 12
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Introduction
Backstory
In February of 2014, Rockliff Pierzchajlo Kroman Architects (RPK Architects) were engaged to design a building envelope upgrade for the acute care hospital in Fort McMurray. With an original $35-million budget and November 2018 completion date, the project construction would prove its resiliency by withstanding three major events affecting the overall project schedule; the 2016 Fort McMurray fire, the 2020 flood, and 2020 COVID-19 pandemic.
Designed by Brian Edwards, Architect, on the heels of the energy crisis of the late 1970s, the original hospital was built by PCL in two phases, a tower with offices and patient care beds and a lower single storey for the emergency and surgical suites, with final completion in 1981. It was understood, at the time, that insulation, vapour, and air barriers were foundational to improved long-term performance especially for high humidity enclosures such as hospitals. However, the designers used
From the upper right: New steel stud framing over the existing sheet metal barrier. Fibreglass faced gypsum sheathing. Self adhered internally reinforced SBS membrane with thermally fused laps. Mineral fibre insulation between thermal clips to support the cladding system. At the centre: Membrane adhered to the aluminum curtain wall frame and clamped with an anti-rotation device. Through-wall flashing lapped with membrane. Below right: Old window system still in place. Below left: New glazing in the new curtain wall framing.
Collapsed soffit and failing stucco caused by air leakage.
a novel approach incorporating a sheet metal barrier as part of the tower wall assemblies to provide air barrier and vapour retarder. The material proved excellent in stopping the movement of vapour pressure across its surface, but its implementation did not provide continuity as an air barrier. The sheet metal pieces were connected via standing seams, but penetrations through the system were not addressed. Connections to the cast-in-place lower floors and stairwells proved unreliable, and sealant at the windows did not allow for movement. Additionally, air leakage and considerable thermal bridging was created where HSS frames, used to support cantilevered cladding, penetrated the metal to connect to the main structural system. Windows were internally glazed with blinds between the lights, an innovation to minimize cleaning requirements, but performance did not live up to expectations. After repeated removals of the inner glass to fix the blinds, the seals failed and condensation often occurred between the inner an outer lights. After the first winter of operation, it became evident that the building was extremely drafty and uncomfortable
for staff and patients. Upgrades of the buildings mechanical systems were made, increasing the internal building pressure to ensure that exterior air would not infiltrate into the building. However, this solution further exacerbated the problem of forcing warm humid air through the building envelope. In the winter this resulted in condensation and freezing in the exterior assembly. At its worst this caused ice to build up in the cantilevered portions of the building to the point where soffits collapsed from the building endangering pedestrian and vehicular ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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Renderings from the design process. Additionally, new pressure equalized curtain wall windows with triple glazed panes would be added outside the existing. The approach leaves existing walls and windows in place as enclosure, allowing a continuous envelope to be constructed outside, with minimal disruption to staff and patients inside. Interior window removal and finishing could be scheduled separate from exterior work, a few rooms at a time to provide the necessary flexibility for continuous hospital operations.
traffic below. Additionally, the moisture in the wall assembly started deteriorating the HSS frames supporting the cladding. Main floor walls were more conventional, stucco on sheathing over batt filled studs and polyethylene vapour barrier. These also proved problematic especially with the added building pressure. Condensation from freezing in the stucco layers caused layers to separate and fail. In addition to the complex as-built conditions, this was an operating acute care facility in a northern Alberta climate. Through RPK's early design discussions with the user groups, it became clear that the work would have to be completed through a multi-phase process to limit disruption to the patients within the facility. As the NLRHC is the only major tertiary care facility in the region, the project had to be sensitive to the number of patient beds impacted at any one time. In addition to not imposing bed reductions, the project had to work with sensitive user groups within the facility. For example, the long-term care residents on the fourth floor could 14
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not go without views to the outside for long durations. Also, the mental health unit had specific needs that required exterior views. These constraints drove the design and construction teams to work in close collaboration to reach an acceptable solution that accomplished the goals of the project and yet addressed the concerns of the occupants.
The solution RPK and the design team worked on a solution that would allow the building envelope to be replaced entirely from the exterior, thereby reducing impacts to patients and clinicians. Several design options were investigated with the final solution being the introduction of a PERSIST (pressure equalized rain screen insulated structure technique) building envelope. Following an iterative multidisciplinary design process, the final option selected introduced a new metal stud outside the existing sheet metal and structure, onto which sheathing and SBS air vapour barrier membrane, insulation, clips, and exterior cladding were fastened.
The two main materials for the finish cladding selected were fibre cement panels (Swisspearl) at lower levels and phenolic panels (Trespa) at higher levels. A repeating pattern for the phenolic panels was developed using the three standard panel sizes to reduce waste, yet create a sense of randomization. After tender, we were told by the local Trespa sales representative that this project was the largest use of Trespa in North America (at that time). As part of the design process, a 3D scan was commissioned of the building to provide an accurate record of the exterior. Both deviations from the ‘as-built drawings’ and changes that occurred over time were captured in the scan. Through a competitive procurement process, Delnor Construction was awarded the construction management contract for the project. Through collaboration with Delnor’s preconstruction services, a phasing plan was developed. The sequencing commenced with the five-storey tower being scaffolded in two sections; each an “L” shape with one long and one short face being covered. After completing preliminary budgeting, sequential tendering began.
Fort McMurray's resilience In 2016, initial tenders were complete and the scaffolding company was preparing to mobilize. The group was literally a few days away from beginning to erect
scaffolding when on May 1, 2016, the Fort McMurray wildfire swept through the region. The fire, which affected many neighbourhoods in the community, such as Abasand Hills above the building, came near to the hospital; staff and patients were evacuated, leaving a handful of firefighters to stand guard. Thankfully, there was no direct effect. Had the scaffolding been erected and its shroud in place, that might have been a very different scenario, disastrous for the building, and an enormous hit to the community. The fire touched everyone in Fort McMurray in both the short and long term, and added a number of months to the construction schedule. The next major disruption to the project was the Fort McMurray flood in the spring of 2020. While only the lowest level of the loading docks was in the actual flood plain, and access was affected, the municipality was greatly impacted. The final disruption that the project experienced was the arrival of COVID-19 in March of 2020. With the world moving to lockdown, the project once again experienced delays with respect to both project access and supply chains.
What remains We are very interested to see how the improvements to the building envelope will affect energy consumption. We have reached out to Alberta Health Services and have been told that a major rebalancing of systems within the hospital is underway. We expect to have data available later in 2022.
Thermal scans to confirm air barrier and thermal barrier continuity, by Building Science Engineering, consultants on envelope design, site review and testing. Upper photo is the infrared thermal image. Lower is daylight photo from the same viewpoint. Prime Consultant: Rockliff Pierzchajlo Kroman Architects; Mechanical Engineer: MCW
Project statistics
Consultants; Electrical Engineer: MCW Consultants;
Original Construction Budget: $35,000,000;
Structural Engineer: RJC Engineers;
Final Construction Budget: $32,761,000
Construction Manager: Delnor
Original Completion Date: November 2018
Construction; Photography:32669 Rockliff Pierzchajlo BEE BC 3/31/08 Kroman Architects, Building
Owner: Alberta Health Services; Client’s Building Envelope Consultant: Building Science Engineering Ltd.;
Final 2:19 PM Completion Page 1 Date: December 2020 n
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Anton J. Vlooswyk, P.Eng. Cel: (403) 651-1514 Providing Building Envelope Consulting Services Tel: (403) 287-0888 Across Western Canada Since 1987 Fax: (403) 287-0880 Email: anton@beei.ca
Project team Client: Alberta Infrastructure;
Science Engineering Ltd., Jim Dobie Photography.
Tel: 102,(403) 4029-287-0888 8th Street S.E. Email: admin@beei.ca Calgary, Alberta, T2G 3A5 102, 4029- 8th Street S.E. www.beei.ca Calgary, Alberta, T2G 3A5 www.beei.ca
BUILDING ENVELOPE ENGINEERING INC.
ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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TECHNICAL CHALLENGES OF PASSIVE HOUSE CERTIFICATION AND WHY THE STANDARD IS HERE TO STAY By Peter Dushenski and Veronica Johnson
Above: Cambridge Lofts Penthouse. Right: Vancouver House Bjarke Ingels.
What is Passive House? Passive House is a German-based standard that ensures high-performance building envelopes with the broad mandate of reducing energy loss through the building envelope by 90 per cent. Although the international Passive House Institute (PHI) is based in Germany, it actually has Canadian roots. Following the Oil Crisis of the early 1970s, The Saskatchewan Conservation House (SCH) laid the groundwork for the Passive House Standard as we know it today! Funded and built as a government research project, this early prototype didn’t have many windows and wasn’t what we might call “classically beautiful,” but it was incredibly effective at reducing operational energy demands. Of course, with 1970s glazing technology, it was easier to keep the building warm by reducing glazed area overall. However, given the productivity and mental health benefits of larger windows that have 16
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since then been well demonstrated, particularly with the recent global pandemic, with the benefit of hindsight we can now see that SCH made tradeoffs in the name of efficiency that didn’t translate into occupant well-being. So is there a way to have our cake and eat it too? Can we create a Passive House project that’s efficient, beautiful, and enjoyable to inhabit?
Cambridge Lofts Penthouse In 2011, an Alberta-based curtain wall manufacturer rose to the challenge of building an entirely passively ventilated single-family residence with curtain wall on all four sides. Replacing a mechanical shed on the 19th floor of a former office building turned condominium in downtown Edmonton,
this humble box was transformed by a team of talented architects at Reimagine (formerly Manasc Isaac) into a stunning two-bedroom penthouse in the sky. All of the corrugated steel from the mechanical shed was replaced with fibreglass-framed triple-glazed curtain wall, to incredible effect. Today, over a decade later, the penthouse is still occupied and very much enjoyed, remaining entirely comfortable down to -20 degrees Celcius with just the radiant heat from the floors below. Below such temperatures, as happens in Edmonton, there are a couple of fireplaces that have been installed.
Certifying to the Passive House standard The curtain wall manufacturer officially
GlasCurtain Thermaframe 9 PH model
launched at Greenbuild in Philadelphia in 2013, and since then has become the North American leader in curtain wall thermal performance. As such, certifying to the up-and-coming Passive House Institute (PHI) Standard seemed like a logical move, perhaps even a straightforward one. So in 2017, the company submitted their designs and models to PHI for review, hoping to achieve at least Cool Temperate
780-994-9084
GlasCurtain v1 Passive House Model.
Climate certification (0.8 W/m2K overall system). Turns out, the German Passive House standard was much more difficult to achieve than anticipated! The conventional manner of improving overall curtain wall performance is to increase the centre-of-glass performance, but Passive House closes this convenient loophole by limiting the centre-of-glass performance in
info@glascurtain.ca
Cool-Temperate Climates to 0.70 W/ m2K and to 0.52 W/m2K in Cold Climates, putting greater emphasis on framing and glass edge performance. Given the triple-glazed fibreglassframed curtain wall’s performance on the Edmonton penthouse, the curtain wall manufacturer expected its standard system to meet at least Cool-Temperate climate requirements right out of the box, ie. 0.80 W/m2K overall. Modelling
PO Box 67198 Meadowlark Park, Edmonton, AB, T5R 5Y3
ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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Passive House Tower Cornell. their system with the limited glazing, however, yielded an overall system U-value of only 0.93 Watts W/m2K, nearly 15 per cent shy of the CoolTemperate target. To call this result disappointing would be an understatement, particularly given that several European curtain wall manufacturers had managed the feat of Cool-Temperate PHI certification using highly conductive aluminiumframed systems to achieve their ends. Given the vastly superior thermal properties of fibreglass (200 times less conductive than aluminium), how could the up-start Canadian manufacturer be so far off the mark? Needless to say this early result was a wake-up call to the strict standard by the Passive House Institute with regards to thermal bridging and air-tightness. It is quite simply on another level from any other standard or certification programme in North America. Not that the Canadian company was about to shy away from the challenge, quite the opposite. Now was the time for its design engineers to roll up their sleeves and show the world that Canada can still build world-class products leveraging domestic manufacturing capabilities. But where to start? Clearly the fibreglass itself wasn’t the issue, so it became only too apparent that the other components of the curtain wall system were in need of improvement. So back to the drawing board for new nosing designs, gaskets, screws, and cavity insulation! With this comprehensive redesign 18
AN ABECN/ABECS PUBLICATION
Saskatchewan Conservation House. underway, this also presented the Canadian manufacturer with an opportunity to review and rethink its standard framing system, then based on a design already 10 years old. Thus began the research and development of the company’s V2.0 systems that would not only have the rigorous Passive House Standard in mind, but also nearly a decade of project experience across some of the most demanding climates and environments in the world. The resulting systems would be able to achieve Cool-Temperate certification with a stretch goal of Cold Climate certification, becoming the first system in the world to achieve the demanding Cold Climate level. Focusing on the new Passive House certified system, the Canadian design engineers, with technical assistance from building envelope consultants at RDH Vancouver, as well as financial support of Alberta Innovates, set about sourcing and modelling a variety of different components to selectively isolate and eliminate thermal bridging in this new curtain wall framing system. Leaving no stone unturned, this new system would use a recessed screw chase, stainless steel screws, advanced gaskets with additional air pockets, and custom extruded EPS insulation in the nosing cavity. Combined with the incredible thermal performance of fibreglass, this new framing system turned out to be so highly insulating that it was no longer in the curtain wall manufacturer’s direct scope to limit the most significant thermal bridging remaining, namely
because now the glass edge spacers were the primary thermal bridge. Indeed, for the first time in curtain wall history, the framing system was not the primary thermal bridge in the overall system, it was the insulating glass unit (IGU). Not that selecting and sourcing the required glass was exactly straightforward either. Many ultrahigh-performance glass units, such as vacuum-insulated glass (VIG), have very conductive edge seals that preclude their use in this specific application. So after running a variety of different simulations and talking to some of the top IGU suppliers from around the world, it was determined that larger air spaces between the three lites would be required – 19 millimetre argon-filled spaces instead of the more conventional 13 millimetre spaces – and that a special secondary glass edge seal would also be necessary to meet the stringent PHI thermal performance targets. With supplier letters in-hand, the Canadian curtain wall manufacturer was able to demonstrate - to the Passive House Institute’s satisfaction - not only the technical possibility of this groundbreaking new curtain wall system but also its commercial availability. With IGUs secured and significantly upgraded fibreglass framing ready, the finalized system was certified to PHI Cold Climate criteria in 2019, becoming the first curtain wall system in the world to accomplish this and the first manufactured in North America to certify to any PHI level. With an overall system U-value of
0.6 W/m2K (including frame and glass), the newest Canadian fibreglass curtain wall system also achieved a best-in-class phA+ passive house efficiency class for airtightness and comfort.
very much sorts the wheat from the chaff in an industry where manufacturer claims unfortunately fail to hold up in the field more often than any of us would like.
like all things, it isn’t perfect. To take
Why certify?
Passive House isn’t perfect…
Canada Green Building Council
The Passive House Institute (PHI) in Darmstadt, Germany distinctly certifies two different categories: products and projects. Products are building envelope components that are certified by PHI to provide third-party verification that manufacturer performance claims are accurate and legitimate. For architects, engineers, and specifiers, this verification greatly simplifies product selection during the design process. Designing a PHI certified project can be a very difficult task to begin with. Reducing whole-building energy consumption up to 90 per cent while still making it beautiful, functional, and meeting all building code requirements is an enormous undertaking. Simplifying product selection for these ultra-highperformance projects is therefore facilitated by the Passive House Component Database, which contains many of the world’s highest thermally performing building envelope products as certified by PHI. With this tool in-hand, the availability of PHI certified products essentially fast tracks incorporation of compliant systems into project designs seeking certification.
Although the Passive House Standard has been incredible for sparking innovation and encouraging much better building envelope construction,
Completed projects are then certified by PHI to provide further quality assurance by verifying correct installation of the approved products, particularly as it pertains to air-tightness and energy use. Projects aren’t strictly required to have all products be certified, but it’s typically the case that the vast majority of products are. At the very least, product certification dramatically improves awareness and increases visibility for compliant manufacturers. The level of design and engineering required to obtain PHI product certification is the most demanding in the world, which
just one example, the Standard does not currently consider the embodied environmental impact of certified products, which is something that (CaGBC) has been doing since the introduction of LEED v4 in 2017. This is of particular concern because Passive House buildings are so well-
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insulated and all those additional building materials have to come from somewhere. As such, Passive House buildings typically have higher embodied carbon and higher overall embodied environmental impacts relative to conventional buildings. As with electric cars, this delta may or may not be made up for by operational gains over the lifecycle of the building, depending on carbon and environmental impacts of the grid where the building is located, as well as how long the building is left standing before it’s knocked down or otherwise rendered unfit for service. It’s important to remember just because we’re designing buildings that consume less energy in operation, it doesn’t necessarily mean these buildings will require less energy to manufacture, or even that they’ll have a net-reduction in environmental impact over the building’s lifecycle. Also, front-loading the environmental impact of a building during the manufacturing process does little to meet aggressive global emissions targets. We only have one planet, after all, and the emissions have to go somewhere, particularly in buildings where so many components are imported from overseas, whether from Europe or Asia. Speaking of imported products, global
supply chain challenges will not be news to many of us in 2022, but do you know how many imported products are used in a typical Passive House project? A lot! For example, at the time of this writing there’s currently not a single PHI certified commercial door manufacturer in North America, so all Passive House doors come from overseas. We can only hope that improved product availability is around the corner for the North American market because reliance on imported products might have some cachet (if from Europe) or some costeffectiveness (if from Asia), but it doesn’t take a huge external shock to derail our best intentions. The world seems to be getting more crazy and unpredictable with every passing year, so it can put us in a fragile position to hinge the success of our projects on these niche imported products. Of course, at the moment there isn’t always an alternative, but it shows just how much more buy-in is needed from North American manufacturers if the Passive House Standard is going to succeed here long-term. Another less invisible trade-off from focusing so narrowly on operational energy performance is building aesthetics. Of course energy matters, but so does beauty. After all, the most sustainable
building in the world isn’t the most efficient one, it’s the most beautiful one… because the beautiful building is the most likely to be preserved and maintained for generations to come. Typical Passive House buildings are many things but they’re not always that beautiful. Too often they’re more like bunkers and less like the creative buildings designed by Bjarke.
Bringing it all together All of that being said, Passive House is still the gold standard in the industry. It’s incredibly demanding for manufacturers and designers, and if nothing else is a world-class benchmark for thermal performance and air-tightness of building envelopes. It’s probably not a silver bullet to solve our environmental concerns, but it does an outstanding job of independently validating the best building products in the industry and separating them from the merely adequate. In an age of increasing uncertainty where resilience has more and more appeal for clients, we can expect to see growing demand for Passive House certified projects across North America and beyond. It’s time for all of us, especially manufacturers, to plan accordingly. n
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CASE STUDY:
BLISTERING IN LINOLEUM FLOORING INSTALLED OVER A CONCRETE SLAB-ON-GRADE By Stephen Hunter, P.Tech. (Eng.), FSFE Introduction This case study is about a failure involving blistering in linoleum sheet flooring installed over a concrete slabon-grade in a school constructed on the Canadian prairies. (Photograph 1). It includes a summary of the investigation methodology and observations. There is also a discussion on why the failure occurred and what could have been done to prevent it.
Methodology This investigation started with a conversation to understand the issues. We then reviewed the design and construction documents. This was followed by a visit to the school to review the issues first-hand. During our site visit, the moisture content of the floor assembly was recorded in several locations – both
where the blistering was occurring and where it was not. At some blister locations, the linoleum flooring was cut and removed to examine it and the underlying assembly. To better understand the composition of the concrete slab-on-grade floor assembly as a whole, core samples were taken at several locations.
Observations The floor assembly was illustrated in the drawings as follows (from top to bottom): • Linoleum sheet flooring • 100 millimetre concrete slab • 6 mil polyethylene sheet layer • 150 millimetre granular fill The floor was slightly above grade and Figure 1: Approximate building footprint with the service ducts indicated by dashed lines. The locations of blistering are indicated by red circles.
was bordered on the building perimeter by concrete foundation walls with strip footings. The foundation walls extended approximately 1.5 metres below grade. The foundation wall assembly was illustrated in the drawings as follows (from exterior to interior): • 1 3 millimetre concrete facing above grade • 5 0 millimetre extruded polystyrene insulation panels • 200 millimetre concrete No membrane was shown in the drawings between the foundation walls and either the above grade walls or slabon-grade. No drainage tile was shown in the drawings. During our document review we also learned that two concrete service ducts were present on the site prior to construction. Both service ducts extended through the building footprint. One duct ran north/south and the other ran east/west (Figure 1). The service ducts measured approximately two metres wide by one metre high. During construction, the concrete service ducts were abandoned and filled with soil. They were not blocked or sealedoff where they entered the building footprint.
Photograph 1: Typical blistering in the linoleum sheet flooring. 22
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At each duct location, the full height foundation wall was interrupted and a 0.6 metre high grade beam was
Left: Photograph 2: Large blister with a saturated moisture content.
Right: Figure 2: Exterior view of the as-built condition of the building enclosure at grade.
provided. This created oversized openings for the service ducts to extend through the foundation walls. During our site visit, we observed that the blistering was occurring mainly above the service ducts and near the building perimeter (Figure 1). The moisture content near the surface of the floor assembly was consistently higher where the blistering was occurring (Photograph 2). Where the linoleum flooring was cut and removed at blisters, it was apparent that it had failed adhesively and cohesively (Photograph 3). Mould was starting to develop within the flooring. While taking the core samples, it was determined that a polyethylene sheet layer was not present below the concrete slab-on-grade (Photograph 4).
The material taken from below the slab-on-grade in the core locations was a granular fill. It had a high fines content. That is, it had a lot of small particles that filled the voids between the larger gravel particles.
Discussion
It was assumed that no membrane was installed between the foundation walls and either the above grade walls or slab-on-grade, as one was not shown in the drawings and no polyethylene sheet layer was provided below the slab-ongrade.
The granular material under the polyethylene sheet layer also acts as a capillary break and drainage layer; however, it only performs these functions effectively if it’s composed of coarse gravel with minimal fines.
It was also assumed that no drainage tile was provided, as none was shown in the drawings and there was no record of it being installed during construction. Figures 2 and 3 illustrate the as-built condition of the building enclosure at grade, and the key observations made during our investigation.
In this type of assembly, the polyethylene sheet layer under the concrete slab-on-grade acts as a vapour barrier and capillary break.
Granular fill with high fines content has small pores. As a consequence, liquid water migrates through the granular fill layer via capillary suction. It is also retained. Without the polyethylene sheet layer above the granular fill, water can
Left: Photograph 3: Wet linoleum flooring that failed cohesively.
Right: Figure 3: Interior view of the as-built condition of the building enclosure at grade.
ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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Left: Photograph 4: Typical core sample.
Right: Figure 4: Exterior view of the improved condition of the building enclosure at grade.
migrate into and through the concrete
building from below the slab-on-grade
slab above, mainly by capillary suction.
accumulates between the flooring and
Similarly, without a membrane to
concrete.
provide a capillary break between the
When concrete is wetted, an alkaline
foundation walls and slab-on-grade,
solution is created with a pH up to 12
water can also migrate from the soil,
to 13 (Photograph 5).
through the foundation walls, and into
Water-based flooring adhesives are often
the slab-on-grade.
sensitive to highly alkaline solutions.
The linoleum sheet flooring has
The alkaline solution created under
relatively low permeability to vapour
and within the linoleum sheet flooring
and liquid water. As such, water
appeared to be causing the adhesive to
migrating to the interior of the
fail.
Left: Photograph 5: An alkaline solution is created at the wet concrete surface.
24
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This adhesive breakdown, combined with the pressure associated with evaporating water at the underside of the flooring, ultimately caused the blistering. The presence of water and a nutrient source led to conditions suitable for mould growth. Of course, all of this requires a source of water below the slab. It’s telling that the blistering was concentrated at the building perimeter
Right: Figure 5: Interior view of the improved condition of the building enclosure at grade.
and above the concrete service ducts. As noted, shallow grade beams were provided at these locations, resulting in openings in the foundation walls near grade. It’s likely that water from precipitation was entering the building footprint at the openings provided for the service ducts. The ducts themselves may have also been conveying water below the building. Perimeter drainage tile at grade beam depth would have reduced the amount of water retained in the soil, and thus would have reduced the amount of water entering the building footprint at these locations. It’s worth noting that moisture from casting the concrete didn't seem to be causing the issues. One would expect the issues to be more uniform if the flooring were installed over concrete with a high moisture content. It’s also interesting that there were no issues reported in the southeast corner
of the building where two service ducts penetrated the foundation. This area had permeable carpet flooring, and consequently, the water was not entrapped.
Prevention A few simple measures implemented during design and construction could have prevented this failure from occurring, as illustrated in Figures 4 and 5. There should have been a continuous capillary break to separate the abovegrade assemblies from the soil. A polyethylene sheet layer and coarse gravel with minimal fines would have served this function below the slab-ongrade. This would have prevented water from migrating to and through the floor assembly. Depending on structural requirements, the coarse gravel may be placed over a layer of compacted granular fill with higher fines content. Filter fabric can be placed below the
coarse drainage gravel to separate it from the soil or granular fill below, and minimize the risk of it becoming clogged with fines. In the assembly illustrated in Figures 4 and 5, a self-adhered waterproofing membrane is applied over the top of the foundation wall to provide a capillary break between it and the adjacent slabon-grade and above-grade wall. If these (or similar) measures were implemented at this building, the blistering likely would not have occurred. Ideally, the out-of-service ducts would have also been removed, at least at the foundation walls. This would have permitted the foundation walls to be continuous, and would have reduced the amount of water entering the building footprint. At this site, the improved building enclosure would perform well without perimeter drainage tile. The need for drainage tile should be determined based on project specific conditions. n
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LOCAL LEGENDS:
ALAN DALGLIESH HONOURED FOR CONTRIBUTIONS TO BUILDING SCIENCE By Randy Kiez won a General Motors scholarship, which he used to complete a four-year program in civil engineering at the University of Alberta. He graduated with distinction in 1959 and went on to obtain a master’s degree from Carleton University, furthering his education along the way with PhD studies in Ottawa.
T
he Alberta Building Envelope Council (South) Executive has decided to rename a SAIT (Southern Alberta Institute of Technology) student award in the honour of Alan Dalgliesh for his outstanding contribution to building science in Canada. Alan grew up on a farm in Picture Butte, Alberta and graduated from high school in 1955, achieving first in the Grade 12 provincial matriculation final examination with a 92 per cent average. With these top marks, Alan 26
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Alan applied for a job with the two Canadian railways, the British Columbia forestry service, Shell Oil (for whom he had worked summer jobs), and with the National Research Council Canada. He received job offers from all of them and, deciding on research, joined the Division of Building Research (NRC) in Ottawa the summer of 1959. Alan chose well and enjoyed his 37-year career, with much of his research on the effects of weather on buildings and other structures. As an example of some of his work, first in Montreal and later on in Toronto, he, with the assistance of technical officers Walter Von Toble and Frank Hummel, set up measuring devices on high-rise buildings. They measured wind pressure on the glass and used accelerometers and strain gauges to record building movement. These recordings were a record lasting seven continuous years. The results of the testing conducted at both model and full scale of the Commerce Court West building in Toronto were published in 1982. This
study was invaluable in demonstrating the validity of wind tunnel testing to predict wind pressures and wind-induced responses for buildings. Alan was also willing to share data collected for this project, and it was utilized by subsequent researchers to demonstrate the effectiveness of Canada’s first sloshing water damper on the Commerce Court West building. Over the course of his career, Alan attended several international conferences where he presented research papers and met with fellow scientists from countries such as the United States, England. Australia, Japan, Brazil, France, and Holland, to name a few. The researchers he met doing similar work often became friends. One interesting experience was when Sears Tower officials sent a private jet to Picture Butte, where Alan and his family were taking summer holidays, to fly him to Chicago to investigate the cause of windows falling from the building. Another significant event was when he was invited to join a team investigating the devastating effects of Hurricane Andrew on buildings. Such was the reputation that Alan held in his field of research even at the international level. Later in his career, Alan was seconded for a couple of years to the Ministry of State for Science and Technology, however he eventually welcomed
ONTARIO BUILDING ENVELOPE COUNCIL, BECKIE AWARD The Ontario Building Envelope Council’s most prestigious award to Alan in 2003: “… to recognize individuals who have made a significant contribution to the design, construction and performance of the building envelope. This is a career achievement award and is not based on a single contribution.”
returning to research at Division of Building Research and was soon put in charge (by the new director) of quality assurance of scientific papers written by officers of the Division of Building Research. In 1995, after retirement, Alan and his wife Marlene moved to Calgary where he subsequently became an ABEC member and was instrumental in getting the ABEC online newsletter up and running, which he did for several years. In Calgary, Alan again made interesting friends and contacts. For instance, he worked with John Vlooswyk, whom he knew previously from John’s visits to NRC. Alan collaborated with Jim Posey with whom he worked on several projects. Alan maintained his ABEC membership and attendance until a few years ago contributing along the way. A small sampling of articles which Alan wrote or co-wrote include: •W all moisture problems and CSA's building durability guideline, Dalgliesh, W. A.., 2000 •P lanning for codification of window glass research, Dalgliesh, W. A., 1984 •C omparison of model/full-scale wind pressures on a high- rise building, Dalgliesh, W. A., 1975 •F ull-scale loading test on a valley and hip roof, Dalgliesh, W. A., 1963 •E ffect of thickness and vertical load on lateral strength of masonry wall panels, Dalgliesh, W. A., 1961
in tall buildings, Dalgliesh, W. A., 1988
W. A., Schriever, W. R., 1962 • Wind loads on low buildings,
• Comparison of model and full-scale accelerations of a high-rise building,
Dalgliesh, W. A., 1981 • The strength and testing of window
W.A. Dalgliesh, K.R. Cooper and J.T.
glass, Dalgliesh, W. A.; Taylor, D. A.,
Templin.
1990
• Comparisons of wind tunnel and fullscale building surface pressures with emphasis on peaks, W.A. Dalgliesh, J.T. Templin and K.R. Cooper, 1979 • Wind pressures on buildings, Dalgliesh,
• Wind on buildings, Dalgliesh, W. A.; Boyd, D. W., 1962 Note that a search of the NRC archives shows that Alan has authored 94 papers. n
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FLOODPLAINS OF RIVERS By Ken Zhao
Figure 1: Typical alluvial river valley (diagram by Mandy). Above and left: Figure 2 North Saskatchewan River at Terwillegar Park, Edmonton. A) Aerial view (satellite imagery from Google Earth). B) Crosssection (elevation data from Natural Resources Canada).
resiliency and sustainability of buildings. Understanding the surrounding environment is an important step to getting there.
Foreword When it comes to natural disasters, Alberta is very familiar with the impact it’s had on its communities. Fires have been responsible for the destruction of a variety of communities in the Regional Municipality of Wood Buffalo and other parts of the province for years. The 2016 Horse River wildfire contributed to an estimated $3.6 billion of damage and is considered one of Canada’s worst natural disasters. Alberta is also no stranger to floods. Floods contributed to millions of dollars in property damage in Calgary, High River and Fort McMurray. One of the 28
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top three natural disasters is associated with flooding. The 2013 Southern Alberta floods resulted in approximately $1.72 billion in property damage. These disasters continue to remind us of how fragile we are and that we need to improve our emergency and flood management programs across Alberta. We are seeing more infrastructure being introduced to limit and control fire and floods in high-risk communities. We also see improvements in floodproofing buildings. For this edition, we wanted to provide some background information about flood plains. As building envelope professionals, we’re always looking for ways to improve the
We were fortunate to have a few stories about the devastating events that have occurred and feature building envelop ideas that contribute to resilient buildings located in flood plains. We would like to thank those that came forward with the great stories and articles. In today’s fast paced world finding time to share our experiences is more important than ever. We hope you enjoy the stories and encourage you to send in your ideas for future publications. — Jamie Murphy A floodplain is the normally dryland adjoining alluvial rivers, over which water from the river flows at times of high discharge. Alluvial rivers typically consist of a main channel, floodplains, hillslopes at the formation of the
valley’s side, and terraces (the landscape elevated relative to the modern river), as illustrated in Figure 1. Floodplains are the areas that stretch from the banks of a river to the base of the enclosing valley walls. As described in the Encyclopedia of Geomorphology by Andrew Goudie (2004) , floodplains are formed by inchannel lateral and overbank vertical accretion processes. Lateral accretion takes place within the channel where the river meanders. As the channel migrates laterally by bank erosion on one side, deposition occurs on the side forming a bar, which grows laterally towards the direction of migration and increases in height. Over time, the bar is built up to a level close to bank elevations. When the river receives more water than can be accommodated by the main channel during high runoff seasons, excess water will flow over the banks and sediment to the overbank area, which will result in vertical accretion in the floodplain. For any river, the presence of the floodplains and their extent depend on many factors, including nature of floods, type of river valley and its erodibility. Figure 2 shows a meandering pattern of the North Saskatchewan River at Terwillegar Park, Edmonton and the shape of the river valley cross section.
channel, the river would flow higher and faster. The extent of floodplain inundation depends in part on the flood magnitude, which is usually defined by the return period. In Alberta, the minimum design standard is the 100-year flood, of which the magnitude has a one per cent chance of being equalled or exceeded in any given year. Detailed hydrology and hydraulic studies are usually required to delineate the 100-year floodplain. The Government of Alberta manages the production of flood studies and maps under the Flood Hazard Identification Program. Flood inundation maps have been produced for many municipalities across the province (available at https:// floods.alberta.ca/). These maps are intended to depict flood risks for a community and to inform local land use planning decisions, flood mitigation projects, and emergency response planning. The area of land that will be flooded during the 100-year design flood is defined as the flood hazard area, which is typically divided into two zones: the floodway and the flood
fringe. The floodway typically incudes the main channel and a portion of the floodplain where flows are considered being deep, fast, and destructive. The flood fringe is the floodplain area outside of floodway where the flow is generally shallower (less than one meter deep) and slower (less than one meter per second in speed). In Alberta, new development in the flood fringe may be permitted but not in the floodway. While floodplains are often flood hazard areas, they provide a river more room to attenuate and store flood flows and thereby reduce the flood risk of surrounding and downstream areas. Floodplains also provide other benefits of economic, social, and environmental value. They improve water quality by retaining excess sediment and nutrients and provide essential habitat for wildlife. Deposition of nutrient-rich silt and sediment often makes floodplains fertile agricultural areas. Mr. Can Hua (Ken) Zhao, Ph.D., P.Eng. is a hydrotechnical engineer and principal with Northwest Hydraulic Consultants (NHC). Ken can be reached at kzhao@nhcweb.com. n
The main river channel normally carries low to average flows. As the inflow increases due to high runoff and exceeds the channel capacity, water will spill onto floodplains, and the rate of river level rise will decrease. The flow of water on the floodplain is shallower and slower than that in the channel as the floodplain offers a greater flow width and higher surface roughness if vegetated. As such, floodplains provide a river more room to convey floodwater and to attenuate flood waves. If floodplains are occupied (e.g. due to development) restricting flows in the ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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HOW TO PREVENT COMMON BASEMENT LEAKS: TIPS AND RECOMMENDATIONS FOR PROPERTY OWNERS By Violet Lim
I
f you have a leaking basement, it doesn’t mean that your home wasn’t built well. Time works against older homes, though older residential buildings can just be as susceptible as brand new ones. Concrete foundation walls can just be as vulnerable as those made of masonry or concrete block units. In most cases, leaks are a result of an unfortunate combination of time and forces of nature. Concrete inevitably cracks somewhere and at some point in time, and sometimes these cracks extend the width of a basement’s foundation wall (i.e., through-cracks), allowing water in saturated soil to seep through.
little water and allow fast drainage, while clayey soils are very absorptive and potentially expansive when saturated. If water is not adequately discharged via weeping tiles to a municipal storm drainage system, surface soil can become saturated during heavy rain or snowmelt events. Additionally, blocked or clogged gutters and downspouts that do not extend away from the building or home will discharge large volumes of water adjacent to the foundation.
What are the usual root causes?
3. S ometimes, a backsloping or negativesloped yard (i.e. the yard slopes towards instead of away from the building) will direct large volumes of water to the building and create hydrostatic pressure against the wall. Again, if the wall is not adequately waterproofed, if cracks are present, and the water has nowhere else to drain (i.e. no weeping tile system at the foundation footing to direct water to a storm sewer system), then leaking will occur into your basement.
The usual suspects of basement leaks result from one or more of the following causes: 1. H ydrostatic pressure occurs when the soil below the foundation and/ or around the foundation walls is saturated with water. This creates pressure against the foundation slab from below and/or against the walls. If the walls are not adequately waterproofed, or if there are throughcracks present and the water isn’t properly drained away from the foundation wall via a weeping tile system at the foundation’s footing, this could force water into the basement. Some soils, like sand or loam, absorb 30
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2. I f the top of a foundation wall is below the surface soil grade, seepage is also likely to occur over the top of the wall during heavy rain or snowmelt events.
4. A foundation wall that has too little steel reinforcement sometimes results in structural cracks that typically extend the width of the wall, allowing water to seep through. Bowing foundation walls and/or horizontal cracks at or
near the mid-span of the basement wall are indicative of inadequate steel reinforcement within the walls. The most common source of water seepage is actually through nonstructural cracks in a concrete wall. Both structural and non-structural cracks require different repairs or combinations of repairs. 5. Sometimes, the cause is obvious. Window wells typically have drains installed within the wells, in case water accumulates from heavy rain or snowmelt events. However, if a drain is clogged or missing, water will enter around the window or push the window in.
What tips and suggestions do you have for preventing leaks of this specific type of building? Basement leak repairs can be typically performed from the inside or the outside, and can be done on concrete, cement block, or masonry foundations. There are several ways to repair existing leaks and prevent future ones into your basement. 1. Install a waterproofing membrane on the exterior side of the foundation wall. This would require excavation of soil to facilitate the installation. At the same time, if not already installed, it would be of great benefit to add an exterior weeping tile or drain system. It’s a belt-and-suspenders system designed to reduce hydrostatic pressure during heavy rain or snowmelt events, and to direct large volumes of water away from the foundation wall to the storm sewer system. 2. If the grade is backsloped towards
the house, while you have the soil excavated as in 1) above, now is the time to properly re-slope the grade away from the building. 3. I f there are structural cracks present in the concrete wall, it could be a sign that the structure is shifting or sinking, or that there is inadequate steel reinforcement within the wall. This is the time to consult a structural engineer. If the structure is shifting or sinking, there is a structural or foundation issue, and structural repairs may be required. If the engineer deems that the cause is inadequate steel reinforcement within the wall, the wall then needs to be stabilized, usually in the form of supplementary steel reinforcement installed in the basement interior. Both structural and non-structural cracks can be sealed from the interior via expanding polyurethane crack injections, which is an expanding, flexible material that fills and seals the crack. If the cracks are narrow enough, they can be bridged with an exterior waterproofing membrane, as noted in 1) above. A combination of the two repairs can be used.
damage and weaken the structure if not dealt with in time. Your home could be deemed unsafe to live in, and this could lead to even more costly repairs, so it is crucial to detect any moisture ingress as early as possible.
About A multi-faceted engineer, Violet’s education combines civil and structural
engineering and her career path has moved from a structural design focus to structural restoration and project management. As a project engineer in RJC’s building science and restoration team, Violet brings practical solutions to projects and fills a key role when structural assessment and design are required. Her clients include commercial property managers, condominium boards and managers, and public entities such as Alberat Health Services. n
High Performance Engineering Services Building Enclosures Building Energy Modelling Façade Engineering Waterproofing Investigations & Evaluations
4. W indow wells that don’t have drains should have ones installed that direct water to the weeping tile system below or away from the building. Clogged drains should be inspected regularly and cleaned of debris. Window well covers keep out debris and minimize the chances of a drain from being clogged.
What are the implications of a leaky foundation if left unchecked? Water is the source of most building issues, so if you have leaky foundation walls, the issues can exacerbate or compound if delayed or ignored. 1. I f you have gypsum board drywall covering your interior basement foundation walls, the presence of water promotes the growth of mould, which is dangerous and harmful to your health. 2. Leaks could cause further structural
RJC Engineers
rjc.ca
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INDUSTRY EXPERT Q&A:
BRIAN SHEDDEN
B
rian Shedden, BSS® is a principal for Entuitive who honours the origins and past of the building envelope industry, while also embracing all its new technologies and discoveries. Read on to learn more about his career highlights and goals.
How did you come to specialize in building envelope? BS: I first started my career in building materials back in 1980. I have always been drawn to things like insulation, siding, windows, doors, and roofing materials. Throughout my career, I’ve always been involved in what today we call building envelope. It wasn’t
How long have you been principal with Entuitive, and what does your firm offer that differs from other building science consultants?
described as such back then; not until the late 1980s did we come
BS: I have been a principal with Entuitive since 2016, but I’ve been with Entuitive since 2013. Our offerings include advanced performance analysis, and abilities to recreate buildings in a digital medium. We also provide sustainability and carbon reduction consulting, both of which are critical elements on the march to net zero. For existing buildings, we work on very focused aspects of the building envelope and address them holistically, rather than just where they seem to be having problems. For new construction, we bring the entire building science arsenal to bear as you only get one chance to build it right. We also creatively collaborate with all of the different team members, whether it be a building owner, architect, government, or municipality. We understand how those businesses operate so we can tailor our services to meet their requirements. Responsiveness is key; it’s not just when we can get around to it, it’s right now.
a critical part of understanding our carbon footprint and energy
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up with the term ‘building envelope’. It’s really a business I’ve grown up in, and there’s so much to learn. It has become such consumption these days. I find it interesting, especially living in a cold climate country like Canada. I really think it’s a good idea to have a good parka, and that’s basically what the building envelope is. It separates the outdoor environment from the indoor environment so we can carry on with our lives. What advice do you give when you meet someone wanting to specialize in the field? BS: There are very limited post-secondary institutions in Canada that specialize in that field – Waterloo, Ryerson, George Brown, BCIT, and a little bit in Concordia. They’re a rare breed that come out of the engineering or architectural technology disciplines, so if they are interested, then we are interested in them. Anyone looking at getting into the building envelope business has a bright, bright future.
How do you see the role of the building envelope specialist changing in the future? BS: With the advent of the National Energy Code of Canada for Buildings (NECB) and what we’re seeing in various municipalities such as in Vancouver, Toronto, and now New York, they are beginning to regulate the performance of buildings. One of the biggest factors that has remained unregulated to date has been the building envelope and the role it should play until very recently. As we march down the path towards net zero, which is a target between 2030 to 2050, we really have to understand that the operations of our buildings represent 40 per cent of our carbon footprint. The only way we’re going to get that under control is if we really embrace what building science and building envelope can do for us to help us achieve those goals. Is there a specific change in building envelope construction that has had a large positive impact? Or a large negative impact? BS: On the positive impact side, I would say the move towards exterior insulation and addressing thermal bridging; these two issues are at the forefront right now. The thing that has had the worst impact is being allowed to construct all glass-clad buildings, which has no insulation in the vision field. The reality is that all-glass buildings are ridiculous almost anywhere. It’s like a terrarium in the summer; you’re going to roast. In the winter, you’re going to freeze. Throwing carbon-based heating and cooling at these buildings only contributes to increased carbon footprints. Do you see other changes coming in envelope design or construction? BS: Yes. In fact, they come out every day. It’s such an incredible field, with the technology that is being developed to help us better understand the building envelope, and not just for those who practice building science. Our clients are finally being able to see, in real time and with project-specific data, the differences that their choices make. Frankly, it’s hard to keep up with the rate of new systems and assemblies coming out, and it’s requiring those of us in the building science field to specialize in one aspect or another in order to keep on top of it. Things like commissioning building envelopes is a brand new thing, and that’s basically making the building prove it was built properly and that all the new assemblies and connections are working. That has never been done before. Things continue to evolve and grow at an exponential rate, and I don’t see that letting up in the near future. n
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VISIT US ONLINE KELLERENGINEERING.COM CALGARY 403-471-3492 | EDMONTON 780-884-7378
ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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In coastal areas, the first level should be used for parking and storage.
Build as high as you can. The higher the better.
DESIGNING FOR FLOODS
Don’t get hit by a wave… Don’t get too wet… And make sure you dry… Courtesy of Joseph Lstiburek, Building Science Corporation Visit www.buildingscience.com for more insights
T
he best way to design for floods is to build in places where you don’t get floods. Yeah, right. We have gotten pretty good at predicting flood risk. The Federal Emergency Management Agency (FEMA) has identified Special Flood Hazard Areas (SFHA). We just don’t pay much attention and build there anyway. So if I can’t convince you to not build there, I will try to help you reduce your risk. The new buzzword for this is “resiliency”. And yes, we were here before, more than once (Rebuilding After Katrina, ASHARE Journal, November 2005 and Rebuilding Houston, ASHRAE Journal, November 2017).
Raise heating, ventilation, and cooling (HVAC) equipment above the base flood elevation (BFE) to prevent damage. 34
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Here is a bit of background information. There are three common types of flood events:
Figure 1a, 1b, 1c: All flood risk is reduced where the slope of the land directs water away from the building and where the building floors are located above the base flood elevation (BFE). Raised slab and elevated pier foundations tend to be more robust and lower risk than slab foundations and crawlspace foundations. • Fluvial (“river”) floods;
sloping away from the building (Figures
Raise heating, ventilation, and cooling
• Pluvial (“flash floods and surface
1a, 1b, and 1c). Build as high as you
(HVAC) equipment above the BFE to
can – the higher the better. In coastal
prevent damage (Photograph 3). Raise
areas the first level should be used for
electrical components at least 12 inches
parking and storage (Photographs 1 and
above the BFE (switches, sockets, circuit
2).
breakers, and wiring) in order to reduce
water”) floods; and • Coastal (“storm surge”) floods. For all of them, the basis of flood resistance or “resiliency” includes the following: • Elevate structures; • Protect service equipment; • Ensure that flood waters enter and exit the house; and • Design and construct building assemblies that are able to get wet during a flood event, readily cleaned and subsequently dried. First, the obvious. All flood risk is reduced where the building floors are located above the base flood elevation (BFE) and where the slope of the land directs water away from the building. Raised slab and elevated pier foundations tend to be more robust and lower risk than slab foundations and crawlspace foundations. Let me repeat: with all foundation approaches, floors should be constructed above the base flood elevation (BFE) with the grade
Figure 2: Concrete masonry unit (CMU) assembly – The first floor assembly is masonry internally insulated with non-water sensitive rigid insulation. The second floor is wood framed with continuous exterior rigid insulation and an insulated frame wall cavity. The roof assembly is a traditional vented attic. ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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damage to the electrical system and the
above the wetting line. The use of non-
for Business and Home Safety
chance of fire from short circuits.
water sensitive rigid insulation such as
(IBHS). I sat through many of their
Figure 2 illustrates the use of concrete
extruded polystyrene allows cleaning
presentations in the early 2000s, and
of rigid insulation surfaces. All wood
they have relentlessly warned us about
framing surfaces on the interior of the
how powerful a wave is. I have been
CMU walls as well as interior wall
shamelessly using the saying ever since.
framing should be coated/painted with
IBHS inspired me to add “Don’t get too
acrylic latex paint prior to installation
wet” and “Make sure you dry” parts.
of interior gypsum board. The coating/
Figure 3 illustrates an alternative
masonry block (CMU) to create a “raised slab foundation”. The first floor assembly is also masonry internally insulated with non-water sensitive rigid insulation. The second floor is woodframed. The roof construction is a vented attic. The interior gypsum board on the first floor should be considered “sacrificial” in that it cannot be readily cleaned, sanitized and dried after wetting. After a flood event wetted gypsum board should be cut away from wall assemblies
painting of all surfaces facilitates cleaning and sanitization after a flood event.
approach – the use of closed cell highdensity spray polyurethane foam (ccSPF) on the interior of the CMU walls and
The “Don’t get hit by a wave” saying
in the second floor frame wall cavity.
comes from the folks at the Institute
Such foam has low water absorption and is not damaged from floodwaters. Again, all surfaces should be coated/ painted with acrylic latex paint prior to installation of interior gypsum board – including the ccSPF. Figures 4 and 5 are variations of CMU “raised slab foundations” but with frame wall assemblies rather than CMU assemblies. Both Figures 4 and 5 have wall assemblies that are insulated externally with continuous exterior rigid insulation. They have no fibrous or batt insulation installed in frame wall cavities to further reduce risk of moisture
Figure 3 – Concrete masonry unit (CMU) alternative approach – Closed cell high-density spray polyurethane foam (ccSPF) can be used on the interior of the CMU wall and in the second floor frame wall cavity. Such foam has low water absorption and is not damaged from floodwaters.
damage arising from floodwaters. Closed cell high-density spray polyurethane foam (ccSPF) is installed in the frame wall cavities. Again, all surfaces should be coated/painted with acrylic latex paint including interior wall framing should be coated/painted with acrylic latex paint prior to installation of interior gypsum board. The spray foam should not completely fill the frame wall cavities, thereby providing an air space that facilitates drying after a flood event. Again, note that wetted gypsum board should be considered “sacrificial” in that it cannot be readily cleaned, sanitized and dried
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Left: Figure 4 – Concrete stem wall raised slab foundation – A variation of CMU “raised slab foundations” but with a frame wall. The frame wall assembly is insulated externally with continuous exterior rigid insulation. No fibrous or batt insulation is installed in frame wall cavities to further reduce risk of moisture damage arising from flood waters.
after wetting. After a flood event, wetted gypsum board should be cut away from wall assemblies above the wetting line. The air gap behind the remaining upper level of gypsum board allows for air
Right: Figure 5 – Empty wall and floor cavities – Fibrous or batt insulation are not installed in wall cavities or floor framing cavities to further reduce risk of moisture damage arising from floodwaters. The wall assembly is insulated externally with continuous exterior rigid insulation. Closed cell high-density spray polyurethane foam (ccSPF) is installed in the frame wall cavities. Such foam has low water absorption and is not damaged from flood waters. Again, all surfaces should be coated/painted with acrylic latex paint including interior.
circulation and drying of the remaining surfaces. Pier foundations must keep air and vapour out of the floor framing/floor assembly. Figures 6 and 7 illustrate perimeter details, connecting the underside of the rigid insulation on the underside of the pier foundation floor framing through the perimeter rim joist area to the exterior wall assembly. Pest and insect control is provided by installing a protection board over the underside of the rigid insulation. Fibercement or cellular PVC boards work well in this regard. The fibercement or cellular PVC boards should be installed using screws to allow for removal should flood waters rise above the floor framing level wetting
framing members. The rigid insulation
Either In or Out, ASHRAE Journal,
should be considered “sacrificial” if
January 2020), there are two common
wetted by floodwaters.
crawlspace foundation approaches;
No fibrous or batt insulation is installed
the crawlspace is either “vented” and
in wall cavities or floor framing cavities to further reduce risk of moisture damage arising from floodwaters. If closed cell high-density spray foam is used in wall or floor framing cavities, it still will need its exposed surfaces to be cleaned even though it is water-resistant. Figure 8 illustrates the use of an elevated concrete floor used in conjunction with concrete piers. Note that the concrete floor is insulated on the top surface to reduce thermal bridging as well as to further reduce risk of moisture damage
cavities. The removal of the fibercement
arising from flood waters.
or cellular PVC boards and rigid
Now onto the “problem child”
insulation and cavity insulation facilitates
foundation: crawlspaces. As mentioned
cleaning and decontamination of
many times previously (Crawlspaces:
“not conditioned” and connected to the “outside” or the crawlspace is “not vented” and “conditioned” and connected to the “inside”. Note that not vented conditioned crawlspaces are not considered occupiable or habitable space. It is not recommended to construct “not vented” and “conditioned” and connected to the “inside” crawlspace foundations in flood prone and coastal regions. Floors above crawlspaces should be constructed above the base flood elevation (BFE). The BFE should be at a minimum 12 inches below the lowest horizontal structural member. Design and construct a crawlspace
ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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that controls flood water by ensuring floodwaters enter and exit the crawlspace without resulting in hydrostatic pressure differences. Water levels in the crawlspace should rise and Figure 6 – Empty wall and floor cavities – Fibrous or batt insulation are not installed in wall cavities or floor framing cavities to further reduce risk of moisture damage arising from flood waters. The underside of the rigid insulation on the underside of the pier foundation floor framing must be connected through the perimeter rim joist area to the exterior wall assembly.
fall at the same rate as the water level outside so that hydrostatic pressures are equalized (Figure 9). Sufficient openings need to be provided to control hydrostatic pressure. Water levels in the crawlspace should rise and fall at the same rate as the water level outside so that hydrostatic pressures are equalized. The total area (size) of all openings serving the crawlspace should be equal to or greater than one square inch for every square foot of crawlspace area. Note that vent openings typically contain a screen or a louver to control the entry of animals and these screens or louvers can block the flow of water. These openings should be distributed over the entire perimeter. Vented crawlspaces must keep air and vapour out of the crawlspace floor framing. Figure 10 illustrates the use of foil faced rigid insulation under
Figure 7 – Pier foundation – Pier foundations must keep air and vapour out of the floor framing/floor assembly. The underside of the rigid insulation on the underside of the pier foundation floor framing must be connected through the perimeter rim joist area to the exterior wall assembly.
the floor framing. The wood is warm and therefore dry during both winter and summer. The foil facing on the rigid insulation addresses the vapour drive. The foil facing is an exceptional vapor barrier (< 0.1 perm). With the impermeable rigid insulation, even relatively impermeable floor coverings such as vinyl flooring and polyurethane coated wood flooring work. The flow of vapour into the assembly (vapour drive) is less than the flow of vapor out of the assembly even with relatively impermeable floor coverings. Adding fiberglass cavity insulation in conjunction with the impermeable foil faced insulating sheathing is a hybrid approach that uses the best qualities
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Figure 8 – Elevated concrete floor – The concrete floor is used in conjunction with concrete piers. Note that the concrete floor is insulated on the top surface to reduce thermal bridging as well as to further reduce risk of moisture damage arising from floodwaters.
of both materials. Note that the optimum location for the airspace is above the cavity insulation. Makes for warmer floors. This is the same detail that should be used under bedrooms over garages. Note that the rigid insulation also needs to be airtight. The seams should be sealed with foil tape. Figure 11 illustrates perimeter details. Again, pest and insect control is provided by installing a protection board over the underside of the rigid insulation. Figure 12 illustrates an alternative approach: the use of closed cell high-density spray polyurethane foam (ccSPF). Such foam has a low vapour transmission – less than 1.0 perm – and can be used with most floor finishes. If closed cell high-density spray foam is used and gets wetted by floodwaters, it still will need its exposed surfaces to be cleaned even though it is water-resistant. It is recommended that sill plates and rim joist framing be treated to be decayresistant. Where floods are concerned, it is good to be “high and dry”:
Figure 9 – Controlling hydrostatic pressure – The crawlspace must control floodwater by ensuring floodwaters enter and exit the crawlspace without resulting in hydrostatic pressure differences.
ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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Figure 11 – Crawlspace perimeter – Note that the rigid insulation also needs to be airtight. The seams should be sealed with foil tape.
Figure 10 – Cavity insulation with vapour barrier – The foil facing on the rigid insulation addresses the vapour drive.
not a difficult situation and one where you were able to control the outcome. Bibliography The Federal Emergency Management Agency (FEMA) has identified Special Flood Hazard Areas (SFHA) that can be found on the Flood Insurance Rate Map (FIRM) (https://www.fema.gov/flood-maps). Protect Your Home From Floods, Institute for Business and Home Safety, February, 2021 https://disastersafety.org/flood/protect-your-home-fromfloods/ Wet Floodproofing – Chapter 6 – Homeowner’s Guide to Retrofitting, The Federal Emergency Management Agency (FEMA), December, 2009 https://www.fema.gov/pdf/rebuild/mat/sec6.pdf n
Figure 12 – Closed cell spray polyurethane foam – If closed cell highdensity spray foam is used and gets wetted by floodwaters, it still will need its exposed surfaces to be cleaned even though it is water-resistant.
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AN ALBERTA BUILDING ENVELOPE COUNCIL NORTH & SOUTH CHAPTERS PUBLICATION Jamie’s Crossword January 2021
CROSSWORD
Jamie’s Crossword January 2021 CLUES
Answers on following page.
ACROSS 2. a Spanish house 5. a small square molding used to separate others 10. lightest wood 12. ______________-build, construction arrangement that combines design and construction services 14. individual firm or corporation submitting a proposal for work 16. a factor that does not vary 17. ability of raw materials to react chemically on heating 18. subdivision of a specification 20. ability of a material to carry an electrical charge from point of high potential to a point of low potential 21. hardwood comes from this type of tree 23. regional animal and plant life 24. part of roof extending above the main roof usually with windows 25. a common method of brick manufacture 27. opposite of condensation 29. air permeability apparatus for measuring the surface area of a finely ground materials (2 words) 32. architectural shield 34. system for measuring electricity named after this French physicist 35. a factor that contributes to produce a result 36. silica gel or calcium oxide is used as this 37. Greatest angle above the horizontal plane (3 words) 40. an instrument for measuring the velocity of a fluid 41. glue made from milk 44. shearing of wood parallel to the grain 45. used as a decorative motif under a cornice 46. also called a binding rafter 47. the half dome of an apse
DOWN 1. a pile of stones used as a marker 3. amount of heat required to raise the temperature of one gram of water through one degree centigrade 4. unobstructed distance between two supports of a beam (2 words) 6. support for wooden steps forming a stairway 7. a piece of brick with one end whole and the other end broken off 8. fibrous mineral used as a fire barrier 9. process involving the infusion of timber with chloride or zinc as a preservative 11. a projecting beam supported at one end 13. piece of lumber with three sides sawn and forth left round 15. a wooden board used to smooth fresh concrete or plaster 17. a mortise which does not pass through the lumber which encloses a stub tenon (2 words) 19. a soft antifriction metal composed of tin antimony and copper 22. negatively charged particle 26. separation of plies 28. one who supervises the construction and keeps a record of materials used (4 words) 30. Spanish glazed decorative tile in which blue is prominent 31. the layer between the bark and wood of a tree 33. an inclination of two surfaces other than 90 degrees 38. disintegration of coatings such as paint manifested by the presence of loose powder evolved from the paint at or beneath the surface 39. type of work not complying with contract requirements 42. a defect of paint or varnish films containing volatile solvents 43. disintegration by electrolysis 48. crooked
ALBERTA BUILDING ENVELOPE COUNCIL / NORTH & SOUTH CHAPTERS
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INDEX TO ADVERTISERS Aegis West Engineering Inc...............................................................................7
Greg Martineau Projects Commercial Limited.........................................IFC
Alberta Sound Exteriors Ltd............................................................................20
Keller Engineering..............................................................................................33
Azon.......................................................................................................................19
Maxim Building Restoration Limited...............................................................7
Building Envelope Engineering Inc................................................................15
Modern Cladding Finishes Ltd...........................................................................5
Cascade Aqua-Tech...........................................................................................25
Oliver & Spence Inc..............................................................................................9
Cooper Equipment Rentals..............................................................................21
PCL Construction Management Inc..............................................................27
Duxton Windows & Doors..................................................................................3
Read Jones Christoffersen Ltd........................................................................31
Engineered Site Products................................................................................21
The Restorers Group Inc.................................................................................IBC
Entuitive........................................................................................................... 7, 33
The RM Group, LLC............................................................................................29
Epic Roofing & Exteriors – Commercial...................................................OBC
Topside Consulting (2004) Ltd......................................................................10
Glascurtain Inc.....................................................................................................17 Jamie’s Crossword
Wade Consulting Inc.........................................................................................21
January 2021
ANSWER KEY
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Building: Renfrew House • General contracting and specialty solutions • Heritage restoration and maintenance • Glazing, caulking, weatherproofing • Concrete, masonry, wall systems • Highrise and lowrise experience
THE BUILDING RESTORATION SPECIALISTS 6230 48 Street SE, Calgary, AB T2C 4P7 (403) 462-6633 | jonathanm@restorersgroup.ca #101, 10813 182 Street, Edmonton, AB T5S 1J5 (780) 239-6760 | dean@restorersgroup.ca
