NZCB InHouse magazine August/September 2020

Page 47

TECH TIPS —

Membrane refurbishment work – what’s consentable? During uncertain economic times, there is a tendency for some new-builds to be cancelled; postponed; or for building owners to consider refurbishment instead.

In terms of membrane roof and deck refurbishment, there’s confusion around what is council-consentable. Many project stakeholders including builders, believe the only viable option is to completely rebuild versus considering an overlay. In many cases, membrane replacements or overlays can legally take place without replacing the existing substrate and supports. More importantly, they will remain robust and code compliant for a further 20+ years. Don’t get me wrong, problematic, poorly designed roofs and decks must be completely replaced and consented. Responsible construction is not negotiable, however tearing down well constructed, compliant structures is unnecessary, expensive and irresponsible even as this adds to the burgeoning waste dumped in our land-fills. Knowing the Building Code could be the difference between projects going ahead or not. Refurbishments render surprising additional revenue during subdued economic times. Below is an over-simplified summary of the intentions of the key Code clauses pertinent to membrane work: E2 ‘External Moisture’ – a roof must shed water, not pond, and keep water out of the building

If an existing membrane roof or deck is sloped less than E2/AS1’s current prescribed minimum, but it: (i) continues to shed water; (ii) doesn’t pond; (iii) remains watertight and (iv) has been keeping people; their property; and neighbours safe for 15 years or longer… then in principle, a comparable membrane replacement/overlay can take place without having to embark on consentable ‘restricted building works’. Admittedly, further conditions apply to the above, e.g.: I recommend invasive testing of the substrate, but hopefully you get the idea.

B1 ‘Structure’ – a roof must safeguard people from injury and loss, and protect other property

If you’re still unsure, get in touch with us on either info@vikingroofspec.co.nz or 0800 729 799.

B2 ‘Durability’ – envelope materials must withstand New Zealand conditions for a minimum of 15 years

This Tech Tip was supplied by Viking Roofspec. Viking Roofspec are NZCB National Partners and specialises in the area of membrane refurbishment. We’re intimate with the Code and more importantly, can recommend robust, compliant membrane or warm roof replacement or overlay methodologies that will stand the test of time.

45


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NEWS BITES

7min
pages 50-53

Easy protection of cut timber ends, with Abodo’s new Protector End Seal

1min
page 49

MiTek screw innovation

2min
page 48

Membrane refurbishment work – what’s consentable?

1min
page 47

Message from our Auckland BDM

2min
page 42

AST Trust update

1min
page 46

ITAB welcomes WITT partnership

1min
page 44

Stay safe, speak up

4min
pages 34-35

Three ways to stop playing the ‘what-if’ game

4min
pages 40-41

Why do I feel so angry?

3min
pages 38-39

Bad vibrations

2min
pages 36-37

To Corporatise, or not to Corporatise? That is the question

5min
pages 32-33

Jump in puddles

2min
page 27

Why you should be using Payment Claims

6min
pages 20-21

Updates from the Building Performance Team

4min
pages 22-23

Beyond green claims

4min
pages 24-25

OUR PEOPLE

2min
pages 28-29

Changes to tertiary education will impact the construction industry

4min
pages 30-31

Meeting your KiwiSaver obligations

2min
page 26

Halo Guarantee update

1min
page 10

Message from the Chief Executive

3min
pages 6-7

NZCB Board changes

3min
page 5

Four reasons why tech is vital post lockdown

2min
pages 18-19

Appliances at commercial prices

2min
pages 12-13

Message from the NZCB Board

2min
page 4

REVERE – submissions now open

4min
pages 16-17

Message from the Group Technical Manager

2min
pages 8-9
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