I've seen this only once, and it was with closed cell foam, but I've heard of it happening with open cell foam, too. I don't know the details, but I've heard it could result from a bad batch of chemicals, improper mixing, or too high a temperature. Whatever the cause, it's not a good thing. The photo below shows how the spray foam pulled away from the studs. A little bit of uninsulated area like that adds up to a lot of heat loss/gain when the whole house has that problem, as it did here.
The local foam installer that I used here in Hilton Head told me he looked for some peeling back of the foam. This was ensuring that it was at the perfect temperature which helped them maximize their yield (profit). I have open cell foam and it pulled away a little, and did so immediately (within minutes). They went back after they were done to any spots that pulled away too much and filled them with the touch up kit; they were looking for the top edge to roll just a little bit. https://youtube.com/e/ggLAUsiuI_o
Good article, but it seems like you can chalk up almost all of those problems to the experience level of whomever is spraying the foam. Spray foam isn't an inherently bad product, but it's pretty easy to botch if the hired company is inexperienced. Fiberglass may be foolproof to install, but then again it has a terrible R-Value compared to a good spray foam. People just need to get referrals and do their homework whenever they research a spray foam contractor.
Due to its relatively large cell structure, low-density foam stays somewhat soft and flexible after curing. This increases the likelihood of its continuing to provide high insulation value even as the building settles and shifts over time. Low-density SPF provides heat insulation and seals airflow through cracks, joints and seams by filling the cavities. In addition, this foam can help absorb sound thanks to its soft texture and open-cell structure.
Spray Foam Attic Insulation
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.
Fill and seal expanding foam sealant is urethane Fill and seal expanding foam sealant is urethane foam designed to fill large areas quickly and permanently. Uses include filling holes cracks or gaps that require a complete airtight and waterproof seal but are too large to be filled with ordinary caulk. The foam expands approximately 3 times its original ... More + Product Details Close
Where Can I Buy Spray Foam Insulation