Closed Cell Attic Foam

A foams r value is its resistance to heat flow or in other words how well they insulate.

Closed cell attic foam.

But some closed cell foams like tiger foam s e84 closed cell formula have even higher ratings that go up to almost 7 per inch. We are going to address the idea of air exchange in closed attics that use open cell foam. One huge benefit of the spray foam insulated attic is that conditioned air leakage from the ac furnace duct system is contained and used to condition the attic. Closed cell foam has a higher r value than open cell foam usually about 6 0 per inch.

Closed cell closed cell is a two component medium density one to one by volume spray applied polyurethane foam. This type of spray foam offers the specific benefits of continuous insulation interior wall cavity fill and unvented attic applications. Open cell foam has an r value of about 3 5 to 3 7 per inch while closed cell foam has an r value of about 6 per inch. Closed cell foam can also increase the racking strength of attic walls which.

But open cell spray foam with a vapor retarder can work too. This medium density spray foam is a closed cell spray foam that is typically used where there is the need for r value insulation per inch possible. I have open cell in my house since 2004 and i would not use it in a dogs out house. That means if you used foam it green closed cell which is r 7 per inch it s r value for a 3 5 deep wall cavity would be r 24 5.

Many builders in cold climates use closed cell spray foam instead because of its lower water vapor permeability which means it doesn t need the extra step of installing a vapor retarder. Open cell foam weighs 1 2 pound per cubic foot and closed cell weighs 2 lbs per cubic foot. When we seal the attic with spray foam it s as tight as a butter tub. Intumescent coatings are not always needed to coat spray foam in the attic in order to meet code thermal barrier requirements.

In a vented attic all of that expensive airflow is lost to the environment. 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. To produce closed cell requires the use of an a component iso and a blended b component resin which contains zero ozone depleting blowing agents catalysts polyols and fire retarding materials. Closed cell foam can also add to the structural strength of the roof system which can make it a more appealing choice in locations that frequently endure high winds.

Closed cell foam can be over three times that with a density of 1 75 pounds per cubic foot or more.