What Is Open-Cell Spray Foam?
Open-cell spray foam is a lightweight, flexible polyurethane insulation that expands to fill gaps and cracks, sealing the space against air leaks.
Lightweight and flexible, open-cell foam works well for soundproofing and interior environments. A4 Global installs open-cell and closed-cell foam, and our team will help you decide which one fits your property.
Best uses for open-cell foam
- Interior walls and ceilings
- Soundproofing between rooms
- Attics and roof decks in conditioned spaces
- New construction and renovations
Open-Cell vs. Closed-Cell at a Glance
Closed-cell foam is denser and insulates more per inch, while open-cell foam is lighter, absorbs more sound and typically costs less.
| Feature | Open-cell | Closed-cell |
|---|---|---|
| Typical R-value per inch* | About R-3.5 to R-3.7 | About R-6 to R-7 |
| Density / feel | Light, soft, flexible | Dense, rigid |
| Sound absorption | Excellent | Good |
| Structural support | Minimal | Adds rigidity |
| Best for | Interior walls, soundproofing | Exterior walls, roofs, commercial structures |
*Typical industry values; exact performance depends on the product and installation. See the U.S. Department of Energy.