If you don t want to use sips or nailbase read this article tolearn the four basic approaches to insulating unvented roof assemblies.
1 2 pound foam unvented roof.
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 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.
Of cellulose insulation in the rafter cavities the roof shown here has an r value of approximately 63.
Foam tech creates superior insulation and environmental control solutions by installing safe cost effective and environmentally friendly polyurethane foams.
However i d need to have an airtight seal for the vb to be superfluous.
It was further assumed that a large enough rafter space was.
Deck for a thick roof rigid foam insulation installed above the roof assembly can create an energy smart roof.
With three layers of 11 2 in.
In the most recent issue of fine homebuilding martin holladay wrote a piece on insulating unvented roof assemblies.
Unvented roof space article 9 19 1 1.
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.
Polyisocyanurate insulation above the sheathing and approximately 91 4 in.
The project in question is a new single family dwelling.
We re big fans of fine homebuilding.
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.
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 spray foam insulation applied to attic roof.
Insulating unvented roof assemblies.
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 are outlined in the.
Foam free don t stay stuck in the sci finightmare of foam foam foam.
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.
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.
1 pound spray foam insulation applied in attic.
Unvented attics insulated with spray foam duration.