Has foil insulation been made a scapegoat?

Last year’s Royal Commission into the Home Insulation Program has the insulation industry at loggerheads, and emotions are running high. What might seem a basic technical matter of managing thermal comfort is anything but simple, with industry experts telling The Fifth Estate about issues as diverse as shonky electrical wiring practices, questionable industry lobbying, energy assessment methodologies that don’t match reality and marketing that ignores the difference between the cool states and the tropics.

For a start, this is an industry with players radically divided across materials lines, according to Ian Hanger QC, who chaired the Royal Commission into the HIP.

The Insulation Council of Australia and New Zealand, which lobbied for the HIP, was in fact just two major companies that make fibreglass batt insulation – Bradford Insulation and Fletcher Insulation, who held about 60 per cent of the market at the time of the RC. ICANZ has since been joined by a third multinational firm, Knauf Insulation.

Calls to the association by The Fifth Estate were not answered.

The Hanger report said even though the original two members both manufactured other types of insulation, ICANZ represented only fibreglass and rock wool interests to the RC. Their other products were represented by another association, as were the polyester insulation manufacturers’, the aluminium foil insulation manufacturers’ and the cellulose fibre insulation manufacturers’.

“The industry was very competitive and fragmented, containing players who spoke up for their own products and against all others,” Hanger said in the report.

How reflective foil became the scapegoat

The casualty of the RC has been the reflective foil laminate sector, with a recommendation by Hanger that RFL be banned nationwide from being retrofitted via installation horizontally across ceiling joists in roof cavities, and be restricted to walls and under flooring.

However, this decision was based on the fact that substandard electrical wiring was in each case a contributing factor to the deaths of installers.

The recommendation is not only a blow for the RLF manufacturers, it is also a concern in terms of a potential formal bar on the type of insulation that works best for preventing radiant heat entering a building.

A 2013 report by the National Climate Change Adaption Research Facility, A Framework for Adaption of Australian Households to heatwaves, recommended modifying roofs by increasing solar reflectance, adding reflective foils and increasing thermal insulation.

It also recommended quality assurance measures of insulation in roofs consistent with regulations in OECD countries.

And that’s where, according to the industry’s leading experts, the thermal comfort baby has well and truly been thrown out with the bathwater.

Non-compliant cabling a major factor

The key message to come out of the RC was not that RLF is inherently dangerous, or that it doesn’t work. Rather it was that the HIP was rushed, the government ignored good advice, electrical risks were inadequately assessed in roof cavities, installers were not given basic training like “do not put metal staples through live electrical cables” and many existing homes have electrical cabling that does not conform to electrical wiring installation safety standards that have been in place since the 1930s.

The RC report states, “One retired engineer, who did not wish to be identified, told the Commission that he perceived a drop in standards from when electrical contractors could certify their own work, rather than have their work inspected by a qualified inspector. Other electrical contractors also contacted the Commission to offer their own observations. Their input is greatly appreciated.

“I accept that in a (perhaps large) number of houses to be insulated under the HIP, the existing wiring did not comply with AS/NZS 3000:2007 or its predecessor regulations. For that, the electrical contracting industry must take responsibility. If the electrical wiring had been in accordance with the relevant standards it is possible that three of the young men [Rueben Barnes, Matthew James Fuller and Mitchell Scott Sweeney] would not have died.”

Under the standard, wiring should be either protected from mechanical damage by being run through a conduit, or fixed to sides of ceiling joists, or have wood blocks placed either side if it runs over a joist so it cannot be damaged by human feet. Also, it means the location of cables is easier to identify.

The other important point made by Tim Renouf from Wren Industries, which provides a concertina-style RLF product, is that the method of installation used by many installers under HIP is not in fact the way it is supposed to have been done at all.

Following the revelations of non-conforming cabling over joists in the HIP, RLF should not actually be stapled to ceiling joists, he told The Fifth Estate, it should be installed so as to be under the roofing rafters and affixed by non-conductive means to them – which in the majority of cases completely takes away the electrical hazard and means the insulation is better at blocking radiant heat.

At this point, Renouf says the RFL sector feels it has been made a scapegoat by the RC for issues that are not the fault of the product, and that the future of RLF firms is at risk.

Why banning RLF from roof retrofits is a bad idea

In the hotter parts of the country, according to leading tropical architecture, insulation and interior airflow expert Dr Richard Aynsley, blocking radiant heat is key.

The former UNESCO chair of tropical architecture at James Cook University, Dr Aynsley told The Fifth Estate that RLF-type foil insulations can block about 95 per cent of the heat that enters a tropical home. And, because the roof is the largest surface exposed to the sun, that’s where the majority of heat is gained.

However, if bulk insulation products such as fibreglass batts are used instead, the effect is like adding a blanket on a hot day. The bulk insulation products will absorb radiant heat, and then release it into the home, and they also prevent heat from escaping. Foil products on the other hand allow heat to escape upwards and do not retain it.

Fire risks

This ability of bulk insulation products to retain heat and prevent it from escaping is something the RC identified as a contributing factor to fires that occurred in a number of homes following HIP bulk insulation retrofits.

“Fire risk emerges in a number of ways. One important way is by the overheating of lamps, luminaires and electrical appliances (such as exhaust fans) in ceilings. The overheating results because air, which would otherwise be circulating around such installations, is unable to escape because insulation has been installed too close,” the report said.

Call for revision of standards

Another difficulty RLF products face is that the testing methodology for the R-value of an insulation product, which is the degree to which it blocks heat transfer, is carried out using an American method designed for cold-climate performance criteria.

This test method is embedded in the soon-to-be-revised Australian Standard AS/NZS 4859.1 – 2002 for insulation materials, Renouf says.

The current standard also has a “motherhood clause” stating thermal resistance in situ may be dependent on surrounding conditions such as the climate and building materials. So while many products carry a label stating an R-value established via a four-hour stationary conductive heat test, Renouf says they may not actually perform to that standard.

The RC recommended that the Australian Standards for installation of insulation, AS-3999 – 1992, also be reviewed. Renouf says this has been done, with the final version of the standard currently awaiting ministerial sign-off. But Renouf warns that AS 3999 must not be printed unless the “partner” standard AS/NZS 4859.1 is also thoroughly revised to account for “environmental factors” rather than the continuation of the historic international test method.

In addition, Hanger recommended the wiring rules be revised.

The building code is part of the problem too

One industry expert told The Fifth Estate that the Building Code of Australia also has problems properly assessing thermal performance, which is used as the determinant of energy efficiency for Section J.

The expert, who did not wish to be named, says the software used to calculate a NatHERS rating has inbuilt parameters that assume the home will use airconditioning, and that it is difficult for assessors that are simply using the software to get a proper calculation for a naturally ventilated home.

“Energy efficiency in the building code is based on thermal comfort, but that is based on a faulty premise,” they say.

Because RFL products have a low R-value according to the conductive testing methodology, it is also difficult to get an accurate assessment of their influence on energy use for cooling homes, Renouf says.

RLF ban a recipe for heat stress

If retrofitting of insulation becomes restricted to the use of bulk insulation products, what this means for homes in cooling-dependent zones is an increase in health risks from heat stress during prolonged hot periods, according to building sustainability expert Graeme Doreian, who gave evidence to the RC.

The heat stress is also felt by airconditioning ductwork located in roof cavities, and there have been cases where airconditioning has failed to operate properly due to the extreme temperatures – up to 60 or even 90 degrees – that can occur in an Australian home’s roof space. That’s a double whammy – a home that retains heat, and airconditioning that won’t work properly to mitigate it.

The heat inside roofing cavities can also affect electrical wiring, as Hanger observed in his report. This is another consideration where bulk insulation only is used in roofs, without the use of a radiant barrier as well.

And the government had been warned

The evidence is that the government was already aware of the issues around workplace health and safety during retrofit installations.

In a presentation to the Senate Inquiry into the Energy Efficient Homes Package, which ran from 2009 until 2010, Dr Aynsley said that the program needed to be modified.

“The existing problems are not the fault of the products”

“Existing housing stock needs to be made more energy efficient and insulation in roofs is the most effective method. The existing problems are not the fault of the products. They are the lack of already defined safety procedures being followed and the large volume of installations occurring,” he said.

His recommendation was that building owners be formally advised of the correct installation process and the safety issues involved in ceiling spaces, are therefore know what to expect and how to get help.

Dr Aynsley also called for amendments to the Building Code, asking that the Senate review the new BCA regulations (expected to be implemented in May), where foil will be forced to combine with other insulation types to achieve the required R-Value.

“This will mean that, in warm climates, heat gain (through roofs, uninsulated walls and through glazing) will be trapped inside buildings at night instead of being able to escape – increasing demand for airconditioning when ceiling fans should be more than adequate,” he said.

2 replies on “Insulation – the problems, the scapegoats and why the Building Code needs amending”

  1. To contribute to this article and the related one INSULATION – HOW TO MAKE THE RIGHT CHOICE, please view some substantial comments I have posted to the INSULATION article.
    The is a great deal of additional information that the energy rating industry needs to read. It appears to me that this complex story kicked of with the Fifth Estate article 2 October, 2014 – FRUSTRATION WITH NatHERS.

  2. That’s a fascinating and revealing article. When I first started to test insulation products for myself the very first thing I found was that every manufacturer of insulation product promoted their own product as the best for ALL situations to the exclusion of all others. They all do that including the maligned RFL manufacturers.

    And on the subject of RFL products, their quoted R values are calculated by computer based on the application. The presumption is that they are working in conjunction with a still space however, as a retrofit practitioner I can guarantee you that very often these products are installed in situations where there is zero chance of a still air space. So what is the resultant R value? It’s anyone guess. The RFL industry needs to take responsibility for this ongoing practice.

    I’m not sure who promoted the practice of laying a reflective blanket over the ceiling joists and then stapling it down but blind Freddy can tell you that once you lay the blanket down it is impossible to remember where the wires are. And even if they are on the side of the joists there is still a chance of stapling through one if it happens to be high up on the side.

    Dr Aynsley is absolutely correct, you need horses for courses. Imagine if Dulux only made internal wall paint and then told you that it was great for the outside of your home and also to spray paint your car with! It’s clearly a nonsense.

    What is needed is more research into safe installation methods that install appropriate insulation in a safe way that still works to insulate the building and leaves the building still able to be maintained. The RFL industry have their work cut out for themselves.

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