1 2 Pound Foam Unvented Roof

In the most recent issue of fine homebuilding martin holladay wrote a piece on insulating unvented roof assemblies.

1 2 pound foam unvented roof.

Just have a contractor install spray foam insulation and you will be much happier with an efficient insulation that actually works and controls moisture. 1 pound spray foam insulation applied in attic. The project in question is a new single family dwelling. We agree that avoiding sheathing rot is critical and that air permeable insulation such as fiberglass or cellulose cannot be used alone.

Unvented roof assemblies should be insulated either with air impermeable insulation rigid foam or spray polyurethane foam or with a combination of foam and air permeable insulation. Ocspf is 1 2 pound per cubic foot open cell spray polyurethane foam ccspf is 2 pound per cubic foot closed cell polyurethane foam. Your comment still stands though there should only be 1 airtight seal. Polyisocyanurate insulation above the sheathing and approximately 91 4 in.

Unvented attics insulated with spray foam duration. Deck for a thick roof rigid foam insulation installed above the roof assembly can create an energy smart roof. Foam tech creates superior insulation and environmental control solutions by installing safe cost effective and environmentally friendly polyurethane foams. 1 spray foam insulation applied to attic roof.

Of cellulose insulation in the rafter cavities the roof shown here has an r value of approximately 63. There are currently two types of spray polyurethane foam spf insulation used in north american residential construction. If you don t want to use sips or nailbase read this article tolearn the four basic approaches to insulating unvented roof assemblies. We have the capabilities to spray and inject a variety of foam systems to achieve a high r value while providing both effective vapor and air barriers.

With three layers of 11 2 in. 5 1 2 inches can be filled or almost filled with 1 2 pound open cell foam or you can go with 3 to 4 inches of 2 pound closed cell foam. It was further assumed that a large enough rafter space was. A roof deck over habitable space is proposed to be insulated with two pound spray foam applied between the joists with no venting between the insulation and the underside of the sheathing.

Since i m attaching the foam to whatever siding is there i haven t ripped out the old insulation yet to take a look i don t know if i ll be able to create an airtight seal. Ccspf or closed cell medium density spray foam 2 pound or 2 pounds per cubic foot and ocspf or open cell low density spray foam half pound or 0 5 pcf. We re big fans of fine homebuilding. Unvented roof assemblies are outlined in the.

All of these materials are supported by quality assurance testing capabilities that. Unvented roof space article 9 19 1 1. Insulating unvented roof assemblies.