Do You Need Attic Ventilation With Spray Foam Insulation. Now we use attic ventilation when we use products like fiberglass because we have to manage the moisture. Ventilation and moisture control in spray foam homes spray foam insulation has been increasing in popularity over the last several years due to. But with spray foam ventilation is not an issue.
Heat from the house rises up to the attic but when there isn t one the heat rises up to the roof. When we seal the attic with spray foam it s as tight as a butter tub.
Spray polyurethane foam is a chemical product that is created by two materials isocyanate and polyol resin that will react with each other when they are mixed and will expand up to 30 to 60 times its liquid volume as it is sprayed in place.
Unvented attic assemblies unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e. However in a traditionally insulated attic insulation on the ceiling the attic is vented. Nothing unusual about that. Rigid foam and spray foam are two of them.
