Closed Cell Spray Foam
As a form of insulation, closed cell is the best option for many types of projects. Because it is a dense insulation, it forms an excellent vapor and moisture barrier that resists the transmission of air and water.
When it is installed, closed cell expands to about 40x its original volume, creating a rigid support and aiding in wall strength.
Since it is such an amazing moisture barrier, closed cell can be installed in places which are likely to get wet, such as basements, crawl spaces, and pole barns.
Closed cell spray foam can be used in almost any situation to create an environment sealed from moisture, vapor and air.
Open Cell Spray Foam
Of the two types of Spray Foam, open cell is the least dense, and hence, the most economical option to install. Despite the lower cost, open cell still provides an excellent thermal and air barrier-- much better than either fiberglass or cellulose.
When it is installed, open cell expands to almost 100x its original volume, creating a semi-rigid, or flexible, insulation. Although it is an effective thermal barrier, it is not a moisture barrier. Water can easily seep through open cell, causing damage and mold to underlying building structures. For this reason, open cell spray foam is typically used above grade-- in the roofline, attic flooring, and in some walls. Open cell also forms an excellent sound barrier, deadening and blocking most noise.