Open Or Closed Cell Foam In Attic

They have different strengths and weaknesses and one is not necessarily better than the other.

Open or closed cell foam in attic.

It s just a pathway. Open cell foam weighs 1 2 pound per cubic foot and closed cell weighs 2 lbs per cubic foot. Open cell spray foam insulation doesn t store the moisture. Open cell is more susceptible to mold and mildew but its expanding so it can hermetically seal an area.

Seems like you wouldnt want to seal something susceptible to mold growth but maybe thats just me. Open cell spray foam insulation is a great choice for attics and the underside of the roof deck. The myth that open cell is more economical is bullshit. The insulation is blown into the wall or attic one layer 1 at a time.

The role of open cell spray foam. Medium density closed cell spray foam ccspf. Open cell foams use water as a blowing agent. 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.

For an open cell the r value is 7. It comes down to understanding the benefits of open cell vs closed cell foam and choosing the type that fits your needs. 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. 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.

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. It s the wood decking that stores the moisture though. Closed cell foams use enovate also known as 245fa. Should i use spray foam insulation in my attic.

How long does spray foam roofing last. Open and closed cell foam insulation use a blowing agent to forms the cells within it. Closed cell is denser better insulating. 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.

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. Spray foam lasts roughly 80 years before beginning to deteriorate. Light density open cell spray foam ocspf. Light density open cell spray foam is commonly known as half pound.

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.