Closed Cell Spray Foam Insulation

Closed Cell Foam Insulation Offers Many Advantages over Open Cell Foam Insulation

By Mark J. Donovan




Closed cell foam insulation is a type of urethane foam insulation that is comprised of tiny closed cells that are bunched tightly together to form an air and water tight seal. Many homeowners and builders choose closed cell foam insulation over open cell foam insulation for a number of reasons.

First, closed cell spray foam insulation has a much higher R-value than open cell foam insulation. R-value is a metric for comparing thermal resistances. Closed cell foam insulation has an R-Value around 5.5 to 6.5 per inch. Open cell foam insulation, on the other hand, is nearly half this value.

Second, closed cell spray foam insulation is also much denser than open cell spray foam insulation. Closed cell spray foam insulation’s density is around 2 lbs per square foot, whereas open cell foam insulation’s density is around 0.5 lbs per square foot.

Consequently, due to its high R-value and high density qualities, closed cell spray foam insulation can provide much more thermal resistance than open cell spray foam insulation in the same space.

Third, closed cell spray foam insulation, when fully cured, provides additional structural integrity to the home. The extra structural integrity can help protect the home from racking and twisting in high winds.

Fourth, because closed cell foam insulation creates an air and water tight seal it can serve as a vapor barrier. A vapor barrier normally needs to be installed over other types of insulation prior to installing the drywall panels.

Closed Cell Spray Foam Insulation

Finally, closed cell spray foam insulation does not require trimming. With open cell spray foam insulation it expands so significantly that after it has fully expanded and cured the excess material that oozed out beyond the stud bay walls needs to be trimmed out with a saw. Trimming takes extra time and creates a lot of mess.

Though closed cell spray foam insulation offers many advantages over open cell spray foam insulation, it is more expensive to install. In addition, with any type of major spray foam insulation project, it should be left to the professionals. Applying too much spray foam insulation in the walls, floors and ceilings can cause drywall panels to bulge and warp.


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