Spray Foam Under Roof Sheathing

Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly.

Spray foam under roof sheathing.

Open cell spray polyurethane foam ocspf and closed cell spray polyurethane foam ccspf insulation sprayed to the underside of roof sheathing is a popular strategy for increasing roof insulation levels in all climate zones. Spray foaming under roof sheathing i need to do something with my house but could use a few answers from someone experienced. Spray foam on underside of roof sheathing. Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.

Moisture generated indoors or that infiltrates into the home is responsible for the bulk of the moisture in an attic insulated with spray foam on the underside of the roof sheathing. Our house was built in 1904 and the square footage of the attic floor is about 1100. Lstiburek takes blame for bad language. Underside of roof decks since the late 60s early 70s and to my knowledge i have not seen or heard of a rotted substrate under and conditions closed cell foam was applied.

Increasingly building scientists are investigating why osb roof sheathing on many spray foam insulated roofs stays damp for months at a time. Install spray foam insulation along the underside of the roof deck to create an insulated unvented attic which can provide a conditioned space for hvac equipment that is located in the attic. Open cell spray polyurethane foam or closed cell spray polyurethane foam ccspf insulation can be sprayed along the underside of the roof sheathing to provide a conditioned and insulated attic space that can be durable and efficient in all climate zones see figure 1. If anyone has please contact me with evidence that being said open cell is a great product as well however in your case you.

Polyurethane or polystyrene spray foams can provide thorough coverage to roof rafters and attic walls in much less time than is needed for other materials.