Spray polyurethane foam, or SPF, is a spray-applied insulating foam plastic that is installed as a liquid and then expands. Many manufacturers offer open-cell, low-density products as well as closed-cell,  two-pound foams. For builders looking for the most cost-effective mix, a hybrid system of the foamed-in-place options may suit their needs.

The 2013 New American Home in Las Vegas did it right. The builder is using open-cell spray foam on the exterior walls and closed-cell for the roof.  Josh Anderson, president of Element Building Co. told BUILDER: "On top of being an incredible water-proofer, it also adds R value to the roof. We're getting an effective R value on the roof in the high 40s or 50s."

As a vapor barrier, air barrier, and insulator, the open-cell insulation from Bayer Material Science that Anderson installed is well-suited for the demands of the Las Vegas climate.

One LinkedIn commenter offered this simple rule: "Where moisture is an issue, closed-cell it is" the solution.

 

Open-Cell Spray Foam

Closed-Cell Spray Foam

Insulation

X

X

Air Barrier

X

X

Typical R-Value

3.7 per inch

6 per inch

Cost

$

$$$

Mold resistant

X

X

Vapor Permeable

X

X

Able to deflect water/
reject bulk water

X

Structural reinforcement

X

Able to accommodate seasonal movement

X

Typical Blowing Agent

Water

Chemical

Suitability

Interior

Interior, Exterior

Learn more about markets featured in this article: Las Vegas, NV.