Open Cell vs. Closed Cell Spray Foam: Which is Best for Louisiana?

When you get quotes for spray foam insulation, you will hear two terms: Open Cell and Closed Cell. Choosing the wrong one for the Louisiana climate will lead to severe moisture problems, mold, and wasted money.

Open Cell Spray Foam

Open cell foam is lighter, less dense, and expands up to 100 times its original size. It is an excellent soundproofer and is cheaper than closed cell.

• Best Use: Interior walls, soundproofing between floors.
• The Danger: It is porous. It allows moisture to pass through it. You should never use open cell foam on the underside of a raised home or in a metal building in Louisiana, as it will act like a sponge for humidity.

Closed Cell Spray Foam

Closed cell foam is dense, rigid, and acts as a 100% complete vapor and moisture barrier. It has a higher R-value per inch, meaning it blocks heat more effectively.

• Best Use: Crawlspaces, attics, metal buildings, and exterior walls.
• The Benefit: Because it dries rigid, it actually adds structural strength to your roof deck and walls, which is a massive benefit during hurricane season.