Open-Cell Spray Foam in Columbia, TN

The lighter, cheaper foam. Air seals well, stays vapor-open, and lets a roof leak show itself.

Open-cell foam is the low-density option, roughly half a pound per cubic foot. It expands aggressively, fills irregular cavities well, and delivers around R-3.7 per inch. It is not a vapor retarder, which is the single most important thing to understand about it.

That vapor openness is usually an advantage on a roof deck. If a shingle fails, water finds its way through open-cell foam and shows up as a stain on the ceiling below, which is how you learn about it. The same leak under closed-cell foam can sit against the sheathing unseen for a long time. The tradeoff is that in a humid climate an unvented attic insulated with open cell needs the indoor humidity managed, because moisture can move through the foam and reach a cold roof deck in winter.

For most attic roof decks in Charlotte this is the material that gets used, at a depth that meets code for the assembly, with the humidity question addressed deliberately rather than ignored.

Typical cost: $1.10 - $1.80 per square foot at typical attic depth

When open-cell foam is the right call

• Roof deck insulation on a house where you want a leak to announce itself
• Interior walls where sound deadening matters as much as R-value
• Filling irregular framing, odd cavities and hard-to-reach bays
• Any job where budget per square foot is the binding constraint

Other services

• Spray Foam Insulation
• Closed-Cell Spray Foam
• Sealed Attic & Roof Deck
• Air Sealing & Blower Door Testing
• Insulation Removal & Replacement

Common questions