OK, Peter, I finally went back and read Alex Wilson's article on what he perceives as a serious problem. I haven't seen the full report, but based on the summary he wrote on the Green Building Advisor website, I question the science. It seems to me that he's chosen the wrong metric and he's basing his conclusion on too many assumptions because he doesn't have enough data. You can see my comments at the end of his article. Coating Services
Installing spray foam is easy to do and can dramatically improve a building or home’s energy efficiency and thermal resistance. Our closed cell foam is so efficient just 3 inches of foam appled inside of wall cavities provides an insulation value of over R18!. Our products are specially formulated for both new construction and existing homes and buildings.
Another type of thermal barrier that can be used instead of prescriptive or approved equivalents is a barrier that has been tested as an alternate assembly. Alternate assembly methods are used to get approval for various types of intumescent coatings. In order for alternate assembly products to meet code, they must be installed and used in the exact same way that the alternate assembly was tested in the laboratory.
While building codes may not require it or enforce it, spray foam should have some form of fire protection. Unprotected spray foam insulation can be a fire hazard. If spray foam is exposed to fire, it can result in a flash fire. Because of this, steps should be taken to protect against fires. Builders who do not use ignition barriers are taking on liability should a house they worked on ever burn down. Coating Services
You've got no argument from me there, Dennis. Getting a good installer if you're going with spray foam is crucial. Many builders or homeowners don't know how to find one, however, and that's where third party inspections come in. Also, even good installers have bad days, but if someone comes in behind them with a measuring probe and a Blower Door, there will be fewer sub-par foam jobs. Spray Coating Services