Closed Cell Foam Vs Open Cell Foam Attic

Calculating spray foam costs.

Closed cell foam vs open cell foam attic. Roofing applications typically use a 2 8 to 3 0 lb cu. In density or even higher for certain applications. 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. Closed cell foam differs in that all of its tiny foam cells are closed and packed together.

Open cell tends to be roughly 0 5 lb cu. Closed cell foam has a higher r value than open cell foam usually about 6 0 per inch. Closed cell foam can be over three times that with a density of 1 75 pounds per cubic foot or more. Open cell spray foam insulation needs to be at full thickness before it can act as an air barrier.

Most open cell foam has a density of about 5 pounds per cubic foot. Open cell foams typically weigh in at 0 4 to 0 5 lb cu. Open cell is not a water barrier it will hold moisture if exposed to the outside environment. Closed cell foam can also increase the racking strength of attic walls which.

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. They are broken and air fills all of the open space inside the material. 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. Ft of foam material is weighed.

Closed cell foam is much denser than open cell foam. Closed cell foam for insulation applications range in density from 1 7 lb cu. This makes the foam weaker or softer feeling than closed cell foam. In density whereas closed cell ranges from 1 7 to 3 0 lb cu.

It is either open cell foam where the tiny cells of the foam are not completely closed. If you need an air barrier as part of your installation closed cell is a better choice. But open cell spray foam with a vapor retarder can work too. Closed cell spray foam insulation acts as an air barrier at any thickness due to its solid properties.

A foams r value is its resistance to heat flow or in other words how well they insulate. Open cell foam is weaker or softer feeling than closed cell foam but a much better sound barrier than closed cell due to the open nature of the cells. To ascertain foam density one cubic foot cu. 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.