The building envelope - Is that a wrap?

By Jess Brunette April 20, 2017 Building Envelope

We look at at what goes on under the cladding and insulates homes from the wind and rain. Jess Brunette reports.

To view a PDF of the complete feature as it appeared in NZ Hardware Journal magazine, click the download button at the bottom of this page


As a key part of the building envelope pre-cladding, as a distinct category from insulation, falls into two very distinct camps; rigid and flexible with the categories generally at odds with each other.

I spoke to players from both camps to get their feelings on the main issues they are facing in a very buoyant construction market.



First stop were key suppliers of rigid air barriers who in many ways are seen as the newer players, at least in New Zealand’s construction market.

IBS Building Products has its EGGER OS’ Brace RAP system and IBSJason Bardell doesn’t mince words in standing firmly behind the benefits of rigid air barriers over their flexi counterparts.

Particularly passionate about the need for further education in the market on the differences between the two product types, he says: “I don’t think all the council building inspectors fully understand the differences between rigid and wrap, bracing elements or even what BRANZ and CodeMark really mean. There’s no national perspective on that.

The historical issue of product appraisals also reared its head. Speaking as an importer of what he feels to be innovative new products, Jason Bardell has found the process frustrating to say the least, with little or no guidance through the appraisal process at Government level and in many cases tending to hinder rather than help the uptake of new products from overseas.

“They put up barriers and there’s no-one to communicate to you at a specifier or buying level and say ‘Yes that product is actually OK. It does meet the standards.’ And if a product is OK in other countries, why is it not OK in NZ?” asks an exasperated Bardell.



And while Jason Bardell’s concerns are definitely shared by many players in the hardware industry, James Hardie’s Singh Kamboj has slightly different concerns, concerning himself more with a lack of skilled installers for the company’s HomeRAB rigid barrier products.

Indeed he takes particular issue with installers who aren’t taking the trouble to read the accompanying manuals or to truly familiarise themselves with the product before beginning an installation.

“That’s when the blame game starts”, says Singh Kamboj somewhat wearily. “One incorrect installation and they will say ‘it’s too hard to install’ or that there wasn’t enough information but any person who is trained as a carpenter should be able to install them.”

And what exactly does he mean by an “incorrect” installation? In Singh Kamboj’s experience, a common example is hasty installers failing to install the appropriate flashings with HomeRAB, leading to leaks as soon as it rains, along with compromises in fire rating and bracing performance.

Despite his concerns around the familiarity of New Zealand builders with rigid barrier products, looking at the bigger picture, James Hardie’s Kamboj is actually very positive about the uptake of their barrier products in the industry, with group home builders, designers, specifiers and homeowners taking to the look and performance characteristics of HomeRAB.



Singh Kamboj is positive around the recent changes to the tenancy tribunal around insulation, even if they don’t affect pre-cladding products specifically.

Seeing as insulation and pre-cladding products are both key links in the overall creation of a home’s building envelope, he feels that the new requirements around insulation could have flow through effects for rigid air barrier products in future.

“I think it’s definitely a step in the right direction and seeing as Rigid barriers automatically add about 12mm of plywood to the exterior of any build, I think that in a couple of years to come there will be a natural shift in the industry to go towards rigid barriers.”



That said, there is still plenty of optimism and confidence for the future from suppliers of flexi barrier products.

To get perspectives from the other side of the pre-cladding fence I spoke first to Nick Batt, General Manager of Marshall Innovations with its Tekton product. He has, like many in the category, been seeing steady business from the area referred to as the “Golden Triangle” with Hamilton, Tauranga and Auckland at its three corners, despite a reported softening of Auckland house consent numbers.

“We have positioned ourselves with a systems-based approach that works well from specification, through the consenting stage onto the merchant channel,” he says. “The builder ends up with a quality system, from one supplier that makes their job simple with no comebacks.”

When I asked Nick Batt for his predictions for the future he feels the market will continue at its current pace with a potential softening in around 12 to 24 months.

He is not alone in thinking this either, judging by reports from around the industry and a dip in the numbers of building consents, the delayed effects of which should be felt further along in the construction process (see our latest market update for more on this).



While Marshall Innovations’ Nick Batt reports good business, word from other players in the industry is that competition in the flexi world is ramping up with lots of players and lots of products crowding the market.

For Antoni Rajwer, Technical & Marketing Leader for DuPont Protective Solutions, a crowded market is far from ideal for New Zealand’s construction industry.

“Certainly for the wrap business, it’s tough out there. There are so many competitors and one of them could service the whole country quite easily. And there is a perception that if you get a BRANZ appraisal or CodeMark approval it will sell, but everyone is struggling because no-one has actually got big volumes.”

DuPont’s Rajwer feels that a glut of products is creating confusion during the build process, with architects, specifiers and building inspectors often having differing ideas about the type of products that are suitable for a project, creating significant delays in completing projects.

Looking to the source of this confusion, DuPont’s Rajwer lays some of the blame on Building Code standards like NZS 2295:2206 Pliable, Permeable Building Underlays that only relate to building papers in the roof and that he feels are now painfully out of date, with many in the industry using synthetic solutions over the last 8-10 years.

Antoni Rajwer admits that appraisal systems do help somewhat to eliminate the confusion, but the buck certainly doesn’t stop there, with some councils refusing the use of some products, he says, despite BRANZ approval.



On the other hand, while CodeMark appraised products are readily accepted by local councils DuPont’s Antoni Rajwer isn’t convinced that they offer the perfect solution in an often confused market.

“The issue around CodeMark is that it’s a very new programme and there’s not a lot of communication around it so a lot of people are flying blind about what CodeMark means and how it applies to the Building Code,” he says.

There are also dangers for those who readily accept CodeMark certified products as one-size-fits-all solutions and Antoni Rajwer for one has heard from many a frustrated designer or specifier working with some CodeMark certified products.

With so many products now available, he stresses that it’s important for specifiers and customers to understand that not all products are the same and research into the specific properties of a product is worthwhile for each application.

“There are products out there that, even with a CodeMark, are very light on technical performance information so it becomes difficult for a designer to recommend them because there’s just no supporting data there,” he says.



On the other side of the issue, Pro Clima’s Richard Eden feels that many of the products that have come into the country recently, particularly those from Europe, will definitely make creating a sound building envelope easier.

In fact, Eden, like his counterpart Singh Kamboj at James Hardie, puts more onus on installers to increase their understanding of the basics of building construction.

“I was on-site recently and had to explain to qualified builders and installers what each individual product’s purpose was for, even though it was part of the Building Code. So there is a little bit of a lack of education out there for the individual layers in the building.”

I ask Richard Eden what he thought would help resolve problems like this. In response he says he shares the feelings of many in the industry that New Zealand’s builders need to revise their attitude to the Building Code and to see it as a “minimum requirement, rather than a target”.

Summing up, the two “halves” of the pre-cladding category are worlds apart.

There are clearly fewer serious players in rigid barriers and they may not face the same degree of market saturation or competition as their flexi counterparts.

But the flipside of this is that the suppliers say they are continually frustrated by unfamiliarity with their products.

Flexi products, on the other hand, are well known in the industry but there are far more players in this arena, possibly more than even a very busy market can sustain.



Changes to the Residential Tenancies Act are endeavouring to make every rental home insulated by 2019. But, with many landlords waiting until the last minute, is the channel ready for the inevitable rush?



New Zealand’s rental properties have been coming under fire for several years now due to a lack of proper insulation that has had negative knock on effects for the health of New Zealand’s rental tenants.

Thankfully, several schemes have been put in place to encourage landlords to get Kiwi homes up to scratch, starting with the government funded Warm Up New Zealand: Heat Smart and Warm Up New Zealand: Healthy Homes programmes run by EECA that started in 2009.

The Heat Smart subsidy has now ended (the effect of which has already been covered in these pages several times) but the Healthy Homes scheme aimed at low-income tenants is still available and covers 50% of the cost of ceiling and underfloor insulation.

EECA’s GM Residential, Robert Linterman, reports that so far around 2,300 landlords have taken up the Warm Up New Zealand: Healthy Homes subsidy with 20,000 more subsidies available on a first in first served basis until the end of June 2018 for properties built before the year 2000 and where the main tenant has a Community Services Card.

The clock is ticking then for landlords to take advantage of the scheme. Compounding the pressure on landlords, and inevitably, the suppliers and installers of installation, are recent changes to the Residential Tenancies Act that will make regulated and correctly installed ceiling and underfloor insulation compulsory in all rental homes from 1 July 2019 where it is “reasonably practicable to install”.

In addition, since July 2016 landlords need to provide a statement in new tenancy agreements disclosing “whether there is insulation in the rental home, where it is, what type and what condition it is in, so tenants can make an informed decision.”

So where does that leave suppliers and installers of insulation? It should be good news but are people looking at their calendars with dread, anticipating an inevitable rush in 2019?



Autex Industries' National Sales Manager, Daniel Szczepański, feels the changes to the Tenancy Act are definitely a step in the right direction but is far from positive about the uptake of products before the due date, reporting that current conversion rates are “very low” despite the 2016 disclosure rules.

“It’s a couple of grand to insulate your house which doesn’t seem a big ask but maybe some landlords just can’t afford it and at the end of the day everyone is going to want it in 2019 and there’s going to be a rush so we’re not going to have the capacity in 2019. And that’s not just Autex but the whole industry,” he reports.



Another insulation player not entirely over the moon with the changes to the Tenancy Act is Phil Jackson of Insulmax, a specialist retrofit installer of insulation for existing walls and ceilings.

For Jackson the frustration comes from the fact that the 2019 requirements don’t include any requirements for exterior walls, an omission he feels is ridiculous given the benefits that a correctly insulated wall cavity can offer.

“Insulating walls will make your house considerably warmer. It will make it feel like a new one so why wouldn’t a CodeMark certified solution like ours be included in any form of government subsidy scheme or the Tenancy Act?”

Jackson’s frustrations are compounded by the “exorbitant” fees charged by some councils for building consent applications with some charging $500-700, up to 10% of the cost of a full installation.

Why so little support for this solution, then?

Jackson explains that, although the Insulmax system only requires a 16mm hole to blow its mineral fibre into each wall cavity, he feels there is a widely held perception that walls cannot be retro insulated without making massive renovations.

To counter this, Insulmax invests considerable marketing resources in educating the market.



Despite Phil Jackson’s frustrations and so far without assistance from the Tenancy Act’s new rules, wall insulation solutions have also been getting some pick up from the merchants.

Among these, PlaceMakers' Insulation Category Manager, Todd Lindsay, has seen steady growth in the commercial arena in products like Kingspan Kooltherm, higher end products that offer the same R values as more traditional fibreglass and polyester solutions at half the volume.

And with Kingspan setting up a new manufacturing plant in Australia in 2016, lead times for Kooltherm have now been shortened to 5-6 weeks from the 11-12 weeks previously needed when arriving from Europe.

Good news but it’s still early days for the uptake of this kind of high R value (and high cost) product so Todd Lindsay’s “bread and butter” in insulation is still the fibreglass solutions which make up around 80% of the market at least in residential properties.

Top of mind for the PlaceMakers Category Manager is the need to engage and motivate landlords to spend money now, rather than in 2019, when there will “most certainly be resource issues and potentially supply issues which could lead to a drop in quality in the installation and potential choke points in the marketplace.”

I ask Todd Lindsay if the changes to tenancy declarations from 2016 had resulted in noticeable spikes in sales but reports from the shop floor are that, while there is plenty of enquiry, actual conversion rates could be as low as 1%.

Todd Lindsay goes on to explain that while it was hoped that the changes around insulation declarations in July 2016 would motivate landlords ahead of time, regions like Auckland with major shortages in rental properties put the odds decidedly in the landlords’ favour taking the pressure off.



Proving this point, Ian Stevens of Mitre 10 MEGA Hornby has seen notable uptakes in Christchurch where, in direct opposition to Auckland, there is a surplus of rental properties.

“Down here if you have a property for rent and it’s not insulated, then it’s just going to sit there empty. So if Property A is well insulated and Property B is not insulated – which one are you going to go for?” he asks.

Backing this up, Justin Macready of PlaceMakers Dunedin has also seen very healthy responses to the tenancy changes in 2016 which makes a lot of sense in a town famous for its inclement and cold weather where students make up 18% of the population.

“There’s a big push around rentals coming up to speed in terms of insulation and smoke detectors,” Macready explains.

“Even the lower end renters are a lot pickier. Students don’t want to live in hovels like the old Scarfies movie anymore. They actually want to live in something nicer and mum and dad don’t mind chipping in a bit of money so Jonny doesn’t catch colds.”

Macready feels that the media coverage of the Healthy Homes scheme has also helped immensely in this trend.

“From a Dunedin perspective, those renters will become home owners in 10 years’ time, so there’ll be a lot more interest in insulation than there was in previous years and people are doing a lot more research now and we’re getting enquiries from our customers about new products like Kooltherm as well,” he says.

In fact, Justin Macready notes that, despite the extra cost, Kooltherm has been doing very well in Dunedin in the last few years thanks to a recent trend for converting old commercial buildings in Dunedin’s central business district into rental apartments.

“These big old spaces have internal masonry walls that are as cold as billy-o and ugly as hell. The traditional way to insulate them adds 100mm per wall which added up takes away significant square metres. Whereas products like Kooltherm offer the same level of insulation for about 60mm and save on labour cost as well.”

PlaceMakers’ Macready also points out that Kooltherm and similar products are already hugely popular in the UK where inclement weather and exorbitant property prices are the norm making these space saving and higher R value products a natural choice but that New Zealand remains fairly traditional in its approach to insulation, at least for now.

And right now it seems that most landlords are doing the bare minimum in terms of insulation before the hammer falls in 2019. Let’s hope that the current trickle will increase to a flow before the pressure builds too much for the industry to handle it…


Kingspan Insulation’s technical bulletin shapes industry thinking

In January this year Kingspan Insulation released a technical bulletin to help industry understanding of the MBIE March 2015 document “Achieving NZBC Group Numbers for surface finishes from tests to overseas standards”.

Kingspan’s “Fire Safety Compliance Guide: Wall and Ceiling Linings” focuses specifically on buildings where insulation is a part of the wall or ceiling lining.

This technical bulletin shows the relevant and correct paths of compliance (for materials used as internal surface linings, in particular for foil-faced combustible materials). It also advises on how to correctly apply the material correlations table for Group Numbers to achieve compliance with performance criteria C3.4 (a) of the NZBC. The “Fire Safety Compliance Guide: Wall and Ceiling Linings” is available for download free from the company’s website.


What’s green and rigid?

EGGER OS’ Brace RAP from IBS Building Products is a high quality, moisture resistant and environmentally sustainable structural bracing panel designed and manufactured for the New Zealand market. This lightweight panel is 11.2kg, comes with a wide choice of flashing tapes and doesn’t require retreatment after cutting. It also creates a quieter internal environment and requires less time on-site.

Panels are treated to H3.1 using a method where the chips are treated prior to being glued together and are made in Germany from environmentally sustainable softwood plantation resources and certified with an Environmental Product Declaration (EPD) according to ISO 14025.

Third party plant certification ensures that EGGER OS’ Brace RAP adheres to international OSB quality standards manufactured under Quality Management system ISO 9001:2004. Several external plant supervision systems, such as CE-marking (European Community), JAS (Japanese Agricultural Standard) or PS2-10 (US Building Code), guarantee superior product quality.

The EGGER OS’ Brace RAP system has been engineered and tested to comply with the performance requirements of the New Zealand Building Code. P21 Structural testing has been completed in New Zealand and Treatment to comply with AS/NZS 1604.2 has been third party verified. The design criteria is based upon NZS 3604 Timber Framed Buildings.

Available in 2440 x 1200 x 6, 2745 x 1200 x 6, and 3050 x 1200 x 6 mm.

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