Does closed cell spray foam shrink over time?
James Olson
Updated on April 26, 2026
But once installed, spray foam, similar to foam boards, will expand and shrink over time. And both open and closed cell spray foam can and do regularly shrink and pull away from other air barrier components.
How long does closed cell spray foam last?
Take a look at the following: Foam is more energy efficient. The R-Value of closed cell foam is 300% that of fiberglass. It's estimated to last for 80 years.Does closed cell foam degrade over time?
Polyisocyanurate (polyiso), XPS, and spray closed-cell foams substantially degrade over time as the insulating blowing agent gases diffuse out and plain air diffuses in.HOW MUCH DOES closed cell spray foam expand?
Closed cell foam expands to approx. 1 inch thick when applied. Open cell foam expands to a whopping 3 inches thick. It's this ability to expand that allows the foam to completely fill every crevasse and open space it encounters, providing a superior air seal that far outperforms other insulation types.Is closed cell spray foam worth the money?
Closed-cell spray foam is the king of the insulations when it comes to both R-value per inch and cost. Nothing else comes close, really. Unlike its open-cell cousin, closed-cell spray foam is not vapor permeable and will not hold water. This makes it an excellent option in case of water intrusion.Spray Foam Insulation — The Ugly Truth?
Does spray foam devalue your house?
In fact, according to Heritage House, they have seen entire roofs rotted and unrecoverable after SPF has been used. They state that by using SPF in your roof, '…you will devalue your home by the amount that a new roof will cost, and more. ' And we agree.Is 2 inches of closed cell foam enough?
Closed cell spray foam should be 4- to 5- inches on the ceiling and 2- to 3-inches in the walls. This might come as a surprise to you, but honestly, this is all the spray foam it takes to get the biggest bang for your buck with the air seal and thermal resistance needed for certain areas of the home.What is the R-value of 4 inches of spray foam?
Spray Foam Insulation R-ValueOpen cell spray foam insulation is R-3.6 to R-3.9 per inch. This R-Value is normal for open cell spray foam.
What is the R-value of 3 inches of closed cell spray foam?
The R-value of closed-cell foam is R-6.5-7 per inch. Contractors often use it to insulate under slabs, ceilings, walls, and roofs. It performs better than other insulation types.What is the R-value of 2 inches of spray foam insulation?
R-Value In 2 Inches Of Spray FoamThe R-value ranges from R-3.5 to R-3.6 per inch. The filling of a 2×4 cavity yields about an R-13.