Before you decide on spray foam or another method of insulation, it's important to understand the superiority of spray foam compared to traditional materials. When compared to fiberglass batts, spray foam offers nearly double the R-value per inch, achieves air-sealing and insulation in one step, won't be damaged by mold or moisture, and won't settle, compress, or otherwise be damaged to the point it needs replacement.
This is in great contrast to my friend's experience. Her attic spaces were sprayed and the foam is actually pretty, and I was in her attic 6-7 days after it was sprayed and could hardly smell anything when I stuck my face up to the foam. And she did not have to clean up one speck of dust during or after the spraying. I got the name/number of the guy from her who managed her attic project, but between the time he did my house and the time he did her house, he was let go from the company who did her attic and hired by another company. He assured me everything would be the same, etc., etc., and I had no reason to believe anything had changed, but the sprayers who did my house later admitted they had never sprayed an attic before and I also found out that the foam used in my attic was from a different manufacturer. Neither my friend nor I had any idea this guy was with different company then, until the week after they filled my attic with off ratio foam, and my home with toxic vapors.
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.
How Much Is A Board Foot Of Spray Foam
The average price to cover 200 square feet with a foam insulation kit will run between $300 and $600 (about two to three kits). Inside these kits is something called Icynene, a foam made from two liquids that are heated and pushed through a gun on the can. When Icynene is released, it expands up to 100 times its size as it hits the surface area you're covering. These can contain a lot of gasses, making its installation a dangerous process. Even low-pressure sprayers can be harmful to homeowners' health.
While coatings may potentially stop minor leaks, the roof should be properly repaired and dried prior to coating application. Coatings may be able to seal pinhole leaks, which are leaks not visible to the naked eye. If the roof is leaking, the roof leak will need to be identified and repaired prior to any recoating; do not expect the coating to find and seal the leaks.
If your foam pulled away just a little bit, Jamie, and they were able to fix it with just a little bit of touching up, then it wasn't as bad as the house where I saw this problem. As the last photo above shows, it had pulled away significantly from the studs and rafters, and it was all over the house. This was closed cell foam, and interestingly, it didn't pull away from the horizontal framing members, just the vertical and sloped ones. They did some touch up, but that wasn't enough. I don't know how this one ended up getting resolved. I think maybe the contractor came back and sprayed cellulose on top of the foam.
The Canadian National Building Code references the CAN/ULC S705.2 National Application Standard which must be followed during all installations of 2lb medium density closed cell polyurethane foam. Every installer of CAN/ULC-S705.1 compliant medium density, spray applied foam must be licensed in order to spray foam and hold valid photo ID issued by their Quality Assurance Program (QAP) provider showing their license is in good standing.