Open-Cell vs. Closed-Cell Spray Foam
Open-cell foam is soft, porous, and vapor-permeable — the economical choice for interior walls, attic air sealing, and soundproofing. Closed-cell foam is dense and rigid, forms a Class 1 vapor barrier at about R-7 per inch, and adds structural strength — the choice for basements, rim joists, exterior walls, and outbuildings. Soundproof an interior wall? Open-cell. Stop moisture in a basement or pole barn? Closed-cell. Most of the enquiries we get from homeowners around Lakewood, CO come in about closed vs open cell foam, and this page sets out how that work runs from the first call through to completion.
| Factor | Open-Cell | Closed-Cell |
|---|---|---|
| R-value per inch | ~R-3.8 | ~R-7 |
| Vapor barrier | No (vapor-permeable) | Yes (Class 1) |
| Soundproofing | Excellent | Minimal |
| Best for | Interior walls, attic | Basements, outbuildings, exterior |
Still deciding? Call (720) 615-8203 for a free recommendation from a pre-vetted Lakewood pro.
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