SPF insulation applied by professionals is usually described as either a high- or low-pressure foam and is available as either open- or closed-cell. Each type has advantages and disadvantages depending on the application requirements. The comparison chart below can be helpful in explaining or understanding which type of SPF insulation is best suited to a specific application.
Open cell spray foam consists of cells that do not completely seal themselves. This makes for a softer and less dense final product. Closed cell foam cells are completely sealed and closed compressed together, creating a denser and firmer final product. This also gives closed cell foam a higher R-value (measured unit of thermal resistance). These differences also affect the cost difference between the two types of insulation.
Where Can I Get Spray Foam Insulation
We had issues with getting this foam to turn green in summertime in the South. We needed up spending an additional $300 on being able to spray this foam: 110 window a/c for shop & a $60 tarp to drape over the top, to keep the temps down. The areas where we had trouble-shooted were sticky & even after we wiped it down, the new green foam wouldn't stick. My husband had to apply Liquid Nails to it. For over $800, I expected alot more, plus the sellers customer service skills were in need of improvement.
What Spray Foam To Buy
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.