Spray Foam Types: Open Cell and Closed Cell

There are two types of spray foam insulation: Open cell and closed cell. The individual characteristics of each type and use of each is outlined below:

Open cell Spray Foam:

  • Foam cells are not entirely closed
  • Light in weight
  • Yields an effective air barrier
  • Lesser expensive of the two types
  • Open cell foam has a higher R value
  • No vapor barrier

Closed Cell Spray Foam:

  • Completely closed foam cells
  • Higher in density than Open Cell
  • Yields an air and moisture barrier
  • More expensive of the two
  • R Value is lower

The nature of the makeup of each type of foam makes each type more suitable for certain environments than the other type.  For example, because closed cell spray foam can also serve as a moisture barrier it is perfect for wet areas such as basements and other under-grade locations.

Lightweight open cell foam insulation is suitable for attics or unvented crawl spaces.  It keeps flexible and soft over its lifetime. It provides insulating value many times per inch thickness what batt insulation or blown in insulation can provide. 

Closed cell foam cures into a hard, durable substance.  It provides rigidity and structural strength to walls and floors 

As open cell spray foam is applied, it expands to 4 times its original thickness and does a much better job of insulating than batt insulation can ever do.  Other advantages of spray foam are that it doesn’t lose its loft, it doesn’t sag over time, or compress like fiberglass or blown in insulation can.

Closed cell spray foam also has the inherent benefit of providing a vapor barrier and deters mold and mildew growth which are concerns in areas such as basements and crawl spaces.

Spray foam is made from eco-friendly polymers that are safe for use in homes and are hypo-allergenic substances that will last longer than any other forms of insulation.