How much polyurethane foam should be applied to the roof decking?
Closed cell foam is the premium preferred insulation product to be applied to the underside of the roof decking due to its ability to diffuse water vapor and create an air barrier seal against the decking. Unvented Roof Assemblies for All Climates. A minimum of two inches of closed cell should be applied. However, open cell can be applied as well but a minimum of 5 inches is the recommended thickness. Unfortunately many foam dealers quote only three inches or less of open cell foam which is doing the homeowner a huge disservice.
Related Questions
- I am building a house with a sealed attic; i.e., with foam insulation applied to the underside of the roof decking. Can I install a gas furnace or water heater?
- Are the costs of a spray foam applied roof higher than that of other types of roofing?
- How much polyurethane foam should be applied to the roof decking?
