Open-Cell Spray Foam

Open-Cell Spray Foam

A Good Choice For Your Home


Open-cell spray foam is the type of foam insulation in which the cells in the product are partially open. It’s sponge-like in consistency and is a very good sound insulator. It has a density of about 0.5 pounds per square foot and an R-value of 3.5-3.6 per inch.

This type of spray foam may have biological raw materials such as soybean oil instead of petrochemicals for part of its ingredients. This makes it a “green” insulation material. Water or carbon dioxide is used for the blowing agent in applying open-cell spray foam.

In applications where space is relatively open, such as attics or crawl spaces, open-cell spray foam is a good choice. Because of its characteristic of allowing some water to pass through, this type of spray foam insulation is also a good choice for residences with wood framing.

Another characteristic of open-cell spray foam makes it very useful in residences. It is more flexible than closed-cell spray foam. Thus, when significant weather or wind impacts the structure, open-cell spray foam will flex with the structure.

The low density of open-cell spray foam makes it economical to use. Less material is needed to fill larger spaces compared to closed-cell spray foam. When comparing volume filled, open-cell spray foam will fill 3-4 times the volume of closed-cell spray foam.

There are some relative negatives that come with open-cell spray foam, as well. One is the requirement of a vapor barrier of some kind with this type of spray foam. The openness of this type of foam insulation means that some water can travel through the insulation. Thus, the need for a barrier.

There are some who say not to use open-cell spray foam directly on the underside of roof sheathing. It appears this sheathing can become wet when this foam is applied directly in this space.

Also, open-cell spray foam is not the best to use in cold climates. Indoor moisture can travel through the foam insulation, accumulate on the cold roof sheathing, and lead to rotting of the sheathing.

Open-cell spray foam is not recommended for outdoor use.

Whichever spray foam insulation you choose, for the best installation of your insulation, choose Weathertight.

Brad Preston, a certified spray foam applicator, and his two brothers, Warren and Brian are ready to put their skills and talents to work for you. Their use of state of the art equipment plus a dedication to customer satisfaction have brought them excellent customer references and significant local support.

Contact Weathertight today at their web site, Or call 603-343-3266. Don’t delay!