Open Or Closed Cell Foam In Attic

Should i use spray foam insulation in my attic.

Open or closed cell foam in attic.

Open cell is more susceptible to mold and mildew but its expanding so it can hermetically seal an area. Closed cell is denser better insulating. Open and closed cell foam are two different types of spray foam insulation. It s expanding properties ensure that it covers every little crack and hole but even with that ability it still needs to be installed correctly.

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. 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. Id go with closed cell. The role of open cell spray foam.

Light density open cell spray foam ocspf. The insulation is blown into the wall or attic one layer 1 at a time. Seems like you wouldnt want to seal something susceptible to mold growth but maybe thats just me. Both low density open cell and medium density closed cell spray foam can be used in an unvented attic to provide the needed thermal resistance and airtightness.

Medium density closed cell spray foam ccspf. Open cell has an r value of 3 7 and closed cell has an r value of 6 5 based per inch of installed spray foam. For closed cell spray foam the r value is 12. It comes down to understanding the benefits of open cell vs closed cell foam and choosing the type that fits your needs.

Open cell foams use water as a blowing agent. They have different strengths and weaknesses and one is not necessarily better than the other. It s the wood decking that stores the moisture though. Spray foam lasts roughly 80 years before beginning to deteriorate.

How long does spray foam roofing last. Light density open cell spray foam is commonly known as half pound. Closed cell foams use enovate also known as 245fa. Open cell foam weighs 1 2 pound per cubic foot and closed cell weighs 2 lbs per cubic foot.

The myth that open cell is more economical is bullshit. For an open cell the r value is 7. This form of insulation is commonly known as two pound foam as it is a rigid insulating material that requires a thickness of 50 mm when applied in the home typically this foam s natural color is yellow when applied in insulation. Open and closed cell foam insulation use a blowing agent to forms the cells within it.

It has a relatively high vapor permeance 3 perms at a thickness of 6 allowing water vapor to migrate to the roof decking at night and back into the attic air in the daytime.