Open Or Closed Cell Foam In Attic

Locally the spray foam installers all recommend open cell.

Open or closed cell foam in attic.

Medium density closed cell spray foam ccspf. Open cell foam weighs 1 2 pound per cubic foot and closed cell weighs 2 lbs per cubic foot. I ve been reading the recent articles that show open cell can lead to roof decking deterioration from humidify coming up through the attic. Icynene open cell and closed cell spray foam insulates and air seals in one step.

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 cell foams use water as a blowing agent. 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.

Their arguments are that when the roof leaks you can tell with open cell. They have different strengths and weaknesses and one is not necessarily better than the other. Closed cell is denser better insulating. It comes down to understanding the benefits of open cell vs closed cell foam and choosing the type that fits your needs.

Light density open cell spray foam is commonly known as half pound. Id go with closed cell. 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 and closed cell foam are two different types of spray foam insulation. Light density open cell spray foam ocspf. Open and closed cell foam insulation use a blowing agent to forms the cells within it. This premiere insulation has many benefits including help with moisture and sound control and the ability to help lower heating and cooling bills.

The insulation is blown into the wall or attic one layer 1 at a time. The myth that open cell is more economical is bullshit. 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. 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.

Open cell is more susceptible to mold and mildew but its expanding so it can hermetically seal an area.