Open Cell Foam Insulation In Attic

When applied on the interior open cell spray insulation provides performance advantages that differ from those of closed cell spray foam used on the exterior.

Open cell foam insulation in attic.

Open cell foam insulation in attics the basic difference. Open cell spray foam is a perfectly acceptable insulation product to use in attics. Insulating value and strength. 20 cm usually it s 18 cm.

Open cell foam weighs 1 2 pound per cubic foot and closed cell weighs 2 lbs per cubic foot. Others like david butler see his comment below say you need to do it only if a moisture problem develops. To be labeled as open cell foam more than half of the cells must be open which means the bubbles. For bigger jobs such as roof attic floor and wall insulation you will need professional help and equipment.

Lstiburek says to do it for every spray foam attic. Architectural firms can specify both the building envelope for a total performance option. An open cell foam low density spray polyurethane is a spray applied to provide continuous insulation and an air sealing barrier. Open cell foam has an insulation value of up to r 3 9 inch while closed cell has an insulation value of up to r 6 9 inch.

Closed cell foam will act as a vapor barrier when installed to a depth of at least 2 while open cell foam won t act like a vapor barrier at any depth. The evaluation service report esr for spray foam insulation products provides a valuable resource based on a third party review of testing information useful for utilizing these products successfully and according to code requirements. An open cell type of foam is mainly used in attics due to its price. Diyers can use this foam for small jobs such as insulating door frames.

This spray foam is applied as a low or high pressure two component polyurethane spray foam that can be applied onto walls in unvented attics to ducts and ceilings and in vented attics and crawl spaces. Closed cell spray foam exterior applications. The minimal layer applied to individual attic elements should have approx. The myth that open cell is more economical is bullshit.

The open cell polyurethane foam has an r value of 3 5 to 3 6 per inch with a price tag of 1 1 20 square foot. Open cell foam has an r value of about 3 5 to 3 7 per inch while closed cell foam has an. There is 300 difference there but the cost they give you is about a third difference and open cell foam at 12 inches will not give you the performance of 2 inches of closed. Do it right and your roof will not rot.

There you have it.