I thought it would be helpful to share this knowledge in NZ as we look to the future of how new houses may be built here. The article is from a Canadian viewpoint on the issues with using spray foam insulation in homes with the cause of unhealthy indoor air.

http://www.cbc.ca/news/spray-foam-in...224287?cmp=rss

I recall some years ago just before building our house in Chch, at the local Home Show there was an outfit based in Auckland selling a similar product. Some of the questions I asked (by email on their website) was not replied (issues like if it's urea based or close cell foam type or if the product meets VOC standards). A reader comment from the news article mentions:

Spray Foam Guy

I have been involved in spray foam insulation for over 14 years. I have worked on both sides of the business and now I am a part owner my own spray foam insulation business.

In response to the gentleman about foam being banned, yes this is correct, but it was urea - formaldehyde or ufi foam. The spray foam insulation that is used and installed today is government regulated to conform to building code, ccmc and also NRC specific standards.

In 14 years, I have seen a few jobs that have gone bad, only one was because of a bad batch of material which was covered, repaired and replaced by the manufacturer. The other have all been by un-certified, untrained installers who think that a spray foam machine is a license to print money.

We belong to CUFCA, the training, regulation and procedures are put in place to protect the customer and to protect the business. One thing that is important in all applications of spray foam insulation is that the applicators are trained and certified. We always encourage any customers to check with the other companies quoting the work that they are certified and trained, and that they ask for licenses.

It's reassuring to see how spray foam insulation is highly tested & regulated in Canada and if a similar regime was done in NZ, I wouldn't hesitate using this product. However, in a similar fashion of the leaky house syndrome in NZ (which points part of the blame from Canada on the use of exterior plaster cladding), if NZ were to adopt spray foam insulation, the building authority better be sure the use and installation of this product is done in a safe manner. Because during the time when Canada had leaky house syndrome from plaster homes, NZ kept on going with building houses with this type of exterior finish without raising an alarm, until say 5 or 10 years later when the damage was apparent.