Open Or Closed Cell Foam In Attic

Open cell vs closed cell spray foam insulation in my attic user 7032327 posted in general questions on march 28 2018 10 52am i am insulation an old brick house with closed cell on the exterior walls and i am tying to decide between open or closed cell under the roof deck in the unvented attic.

Open or closed cell foam in attic.

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. I ve been reading the recent articles that show open cell can lead to roof decking deterioration from humidify coming up through the attic. They have different strengths and weaknesses and one is not necessarily better than the other. Icynene open cell and closed cell spray foam insulates and air seals in one step.

Closed cell foams use enovate also known as 245fa. Light density open cell spray foam ocspf. 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. This premiere insulation has many benefits including help with moisture and sound control and the ability to help lower heating and cooling bills.

Open and closed cell foam are two different types of spray foam insulation. 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. Closed cell is denser better insulating. Medium density closed cell spray foam ccspf.

Open and closed cell foam insulation use a blowing agent to forms the cells within it. Open cell foams use water as a blowing agent. Id go with closed cell. 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.

Open cell foam weighs 1 2 pound per cubic foot and closed cell weighs 2 lbs per cubic foot. 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. Some even claim 5 5 of open cell is a air vapor barrier but i don. Open cell is more susceptible to mold and mildew but its expanding so it can hermetically seal an area.

Their arguments are that when the roof leaks you can tell with open cell. It comes down to understanding the benefits of open cell vs closed cell foam and choosing the type that fits your needs. Seems like you wouldnt want to seal something susceptible to mold growth but maybe thats just me. The insulation is blown into the wall or attic one layer 1 at a time.

Light density open cell spray foam is commonly known as half pound.