1 2 Pound Foam Unvented Roof

Foam free don t stay stuck in the sci finightmare of foam foam foam.

1 2 pound foam unvented roof.

We re big fans of fine homebuilding. 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. 1 pound spray foam insulation applied in attic.

There are currently two types of spray polyurethane foam spf insulation used in north american residential construction. Insulating unvented roof assemblies. 1 spray foam insulation applied to attic roof. In the most recent issue of fine homebuilding martin holladay wrote a piece on insulating unvented roof assemblies.

Unvented roof assemblies are outlined in the. 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. Ocspf is 1 2 pound per cubic foot open cell spray polyurethane foam ccspf is 2 pound per cubic foot closed cell polyurethane foam. 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.

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. 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. 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.

The project in question is a new single family dwelling. If you don t want to use sips or nailbase read this article tolearn the four basic approaches to insulating unvented roof assemblies. Unvented roof space article 9 19 1 1. Your comment still stands though there should only be 1 airtight seal.

All of these materials are supported by quality assurance testing capabilities that. However i d need to have an airtight seal for the vb to be superfluous. Of cellulose insulation in the rafter cavities the roof shown here has an r value of approximately 63. The roof rafter space was assumed to be filled with sufficient insulation to meet the 2009 irc code values based the doe zone listed in table 1.

With three layers of 11 2 in. 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. Polyisocyanurate insulation above the sheathing and approximately 91 4 in.