Open-Cell Spray Foam
Open-cell spray foam expands 100x on application, filling every cavity and crack for whole-home air sealing at a lower cost than closed-cell. It's breathable — letting moisture escape rather than trapping it — and excels at sound dampening, making it the choice for whole-attic coverage and interior walls.
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ProPink fiberglass, installed to manufacturer spec
Before-and-after infrared proof on every job
Local crews, never subcontracted
Transferable to the next owner
Open-Cell Spray Foam for South Florida Properties
open-cell spray foam is the workhorse of Florida attic retrofits. We will tell you plainly when it is the right specification and when a less expensive approach delivers the same outcome.
South Florida sits in South Florida, where the recommended attic target is R-38 to R-49. That number, along with where your ductwork runs and what condition the existing assembly is in, is what determines the right specification for your property.
Open-Cell Spray Foam at a glance
- R-value
- R-3.8 / inch
- Installed cost
- $1.50 – $3.20 per sq ft installed
- Service life
- 80+ years
- Available in
- South Florida and throughout South Florida
Types and Methods
Half-pound open-cell
Expands 100x on application, filling every crack, gap, and penetration. Its open-cell structure is vapor-permeable — letting moisture escape rather than trapping it — which makes it safe for whole-attic applications where a vapor barrier could trap condensation. It also absorbs sound effectively.
Whole-attic open-cell
Applied to the underside of the roof deck, bringing the entire attic within the conditioned envelope. This stops ductwork from running through 140°F air and is the single most effective upgrade for second-floor comfort in South Florida homes.
Open-cell foam is vapor-permeable by design — it lets moisture escape rather than trapping it. This makes it the right choice for whole-attic applications where a vapor barrier could cause condensation. We verify the roof has no active leaks before spraying.
Benefits for South Florida Property Owners
- Expands 100x — seals every crack and penetration fiberglass misses.
- Breathable — lets moisture escape rather than trapping it.
- Excellent sound dampening — ideal for interior walls and floors.
- Lower cost per board foot than closed-cell for large areas.
- Whole-attic coverage that stays sealed for decades.
Best Applications
- Whole-attic coverage on the roof deck
- Interior walls and floors for sound dampening
- Large cavities where breathability matters
- Budget-conscious whole-home air sealing
- Knee walls and bonus room envelopes
How We Install It
- 1FLIR-scan the attic to map existing leaks and thermal bridges
- 2Air-seal top plates and penetrations before foaming
- 3Mask and protect all surfaces below the work area
- 4Spray open-cell foam to the underside of the roof deck to specified depth
- 5Trim overspray flush to rafters and framing
- 6Verify ventilation paths are correctly sealed per the engineered approach
- 7FLIR-scan to verify the seal and document the thermal delta
Cost and R-Value Reference
Florida insulation cost & R-value reference.
Typical installed costs across South Florida by material. Pricing varies with access, square footage, and site conditions — every Cardinal quote itemizes material, R-value, installed inches, and square footage.
| Material | Installed cost | R-value / inch | Service life |
|---|---|---|---|
| Blown-in fiberglass | $1.10 – $2.00 / sq ft | R-2.2 – R-2.7 / in | 20–30 years |
| Blown-in cellulose | $1.20 – $2.40 / sq ft | R-3.2 – R-3.8 / in | 20–30 years |
| Fiberglass batts | $0.90 – $2.10 / sq ft | R-3.1 – R-3.4 / in | 25+ years |
| Mineral wool | $1.60 – $3.40 / sq ft | R-3.0 – R-4.3 / in | 50+ years |
| Open-cell spray foam | $1.50 – $3.20 / sq ft | R-3.6 – R-3.8 / in | 80+ years |
| Closed-cell spray foam | $2.40 – $4.90 / sq ft | R-6.0 – R-7.0 / in | 80+ years |
| Rigid foam board | $1.40 – $3.80 / sq ft | R-3.8 – R-6.5 / in | 50+ years |
| Radiant barrier | $0.55 – $1.90 / sq ft | Reflective (no R) | 25+ years |
| Duct sealing + R-8 wrap | $800 – $3,500 / system | R-8 (duct) | 15–25 years |
| Insulation removal | $1.10 – $2.90 / sq ft | — | One-time |
Pricing reflects typical Florida installed costs and varies with access, square footage, and site conditions. Source: U.S. Department of Energy insulation guidance, Florida Building Code R402, and IECC climate zone 1 requirements.
Pricing reflects typical Florida installed costs and varies with access, square footage and site conditions.
Open-Cell Spray Foam FAQs
Open-cell is ideal for whole-attic coverage, interior walls, and sound dampening where you want breathability and lower cost. Closed-cell wins for roof decks, crawl spaces, and moisture-critical coastal applications.
Yes — open-cell's porous structure absorbs sound waves effectively. It's our go-to for interior walls, ceilings between floors, and media rooms across the tri-city area.
No — that's its key advantage. Open-cell is vapor-permeable, letting moisture escape rather than trapping it. This makes it safe for whole-attic applications where a vapor barrier could trap condensation.
Serving the Boca–Delray–Boynton corridor.
From the Boca inlet to Boynton's western estates — every hot zone below is a home we sealed this year. This is our local service area.
