Open Cell vs
Closed Cell Spray Foam:
What's Right for You?

There's no universal answer. The right foam depends on where it's going, what you're trying to fix, and what the budget is. We'll give you a straight recommendation — not just the most expensive option.

The Key Differences

FeatureOpen CellClosed Cell
R-Value per inch~R-3.7~R-6.5 to R-7
Acts as vapor barrier✗ No✓ Yes
Water resistance✗ Absorbs moisture✓ Waterproof
Structural rigidity✗ Soft / flexible✓ Rigid, adds strength
Expands on application✓ ~100x expansion~30–40x expansion
Cost per sq ft✓ Lower costHigher cost
Ideal for interior walls/attics✓ Yes✓ Yes
Ideal for crawlspaces✗ Not recommended✓ Strongly recommended
Ideal for coastal/flood areas✗ Not recommended✓ Required
Ideal for metal buildingsAcceptable✓ Preferred

Open Cell Foam

When It Makes Sense

Interior attic applications (roof deck)
Interior walls in living spaces
Sound dampening between floors or rooms
Projects where budget is a primary concern
Areas where a vapor barrier is handled separately

Open cell does an excellent job of air sealing and insulating interior spaces. It expands aggressively to fill every gap and cavity.

Closed Cell Foam

When It's Worth the Investment

Crawlspaces and subfloors
Coastal and flood-prone structures
Metal buildings and exterior walls
Elevated camps in bayou/marsh areas
Any application where moisture barrier is critical
Where structural strength is a consideration

In Louisiana, closed cell is often the right call. Our climate, humidity, and flooding risk make moisture resistance critical in many applications.

Not Sure Which Type You Need?

Just call us. Tell us what you're working with and we'll tell you what makes sense — honestly, without just upselling you to the most expensive option.

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