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