What is it?
Spray foam insulation, when applied is a liquid that expands and then solidifies, which totally seals the roof of your home. But by sealing the roof, this also means that air circulation is restricted, and lack of air flow causes condensation. The spray foam is applied between the rafters which means when condensation forms due to the lack of circulation, it will cause the roof supports and rafters to weaken and rot over time, it can also become trapped between the roof felt and the spray foam.