Are you talking about the stuff in cans or the spray rig that puts out polyisocyanurate? The insulating value of even low density sprayed in place foam is much higher per inch than any other type of insulation...except high density foam. We use it to obtain higher R-values in undersized walls or ceilings, for rafters when a cathedral ceiling is desired and there is no way to vent the roof. Highly recommend it. Even at 3 times the cost of fiberglass, the seal is far superior and the results, undeniable.

We are in the process of planning to build a home. There is so much to think about from a wood fire place to geothermal or panelized home versus a stick home? It is overwhelming. We too talked about using SPRAY FOAM INSULATION. Today we talked to a builder that suggested that there now may be some problems with spray foam. It did make us wonder. The side of the house that is exposed to direct sunlight apparently expands with gases & starts to buckle or something. He said something about a rod inserted? When rod was taken out all the gases were released. Which raises question about the safety of the built-up gases. Has anyone heard of this?