Open-cell and closed-cell spray foam compared
| Open-cell | Closed-cell | |
|---|---|---|
| R-value per inch | About R-3.5 to R-4 | About R-6 to R-7 |
| Density | Soft, light | Rigid, dense |
| Moisture | Lets vapor pass; absorbs water | Vapor retarder; resists water |
| Cost per inch | Lower | Higher |
| Sound | Better at dampening sound | Less sound dampening |
| Common uses here | Attic roof decks, interior walls | Under raised floors, crawl spaces, metal buildings |
When to use open-cell spray foam
Open-cell foam is common on attic roof decks in our area. It costs less to reach a target R-value, expands to fill odd shapes, and dampens noise. Because it lets moisture pass, a sealed attic with open-cell foam is often paired with a small amount of conditioned air or dehumidification.
When to use closed-cell spray foam
Closed-cell foam is the better choice anywhere moisture is a concern: under raised floors exposed to outdoor air, on crawl space walls, and on metal buildings that sweat. It also adds stiffness to what it's sprayed on.
Related: attic spray foam · under-floor foam · spray foam cost
How getting a spray foam estimate works
- Call or send a requestTell us what you want insulated and where you are.
- Get a written estimateA local installer measures and quotes foam type, thickness and price.
- Get it installedMost attics are done in a day or two.
Why call us for spray foam insulation
- One callSkip calling around. We connect you with a local spray foam installer.
- Local installersCrews that work in Metairie and across Jefferson Parish.
- Free to useThere's no charge to you for the referral.
- Built for our climateAdvice that fits Gulf Coast heat, humidity and termites.
Hot attic? Get a free spray foam estimate.
Call now(504) 555-0199Spray foam insulation service areas
Spray foam insulation questions
Which spray foam is better for a Metairie attic?
Both are used. Open-cell is more common on roof decks because it costs less per R-value; closed-cell is chosen where extra moisture resistance or rigidity is wanted.
Can open-cell foam go under a raised floor?
It's generally not recommended there, because it absorbs moisture from humid outdoor air.
Request a spray foam insulation estimate
Tell us about the project and a local installer will call you back. Prefer to talk? Call (504) 555-0199.