Greater Houston
Closed-Cell Spray Foam Insulation in Greater Houston
Learn about the dense, moisture-resistant insulation option designed for strength and efficiency. Phantom Foam shares straightforward details to help you decide if it's right for your home or building.
AVAILABLE FOR HOUSTON BUILDINGS
Closed cell spray foam delivers R-6.5 per inch — the highest R-value per inch of any insulation product available. It bonds permanently to metal, concrete, wood, and masonry. It acts as a Class II vapor retarder at standard application thicknesses. And it adds measurable structural racking strength to every wall and roof assembly it is applied to. No other insulation product does all four simultaneously.
- Closed cell spray foam is a rigid, high-density polyurethane material. When the two chemical components are mixed and sprayed, the foam expands 30 to 60 times its liquid volume and cures rapidly into a hard, dense matrix. The "closed cell" name refers to the microscopic structure — each gas-filled cell is completely encapsulated, which gives the foam its rigidity, its high R-value per inch, and its resistance to water vapor and bulk moisture transmission.
- The physical properties that make closed cell foam perform the way it does are all a direct consequence of that closed-cell structure. The encapsulated gas cells act as an extremely efficient thermal insulator. The dense, interconnected cell walls resist vapor transmission — classifying the cured foam as a Class II vapor retarder at 2 inches and approaching Class I performance at 3 inches. The rigid foam matrix bonds to the substrate it is applied to and adds compressive and racking strength to the assembly, which has been documented in third-party structural testing.
- In Greater Houston's Climate Zone 2A — hot, humid, and subject to Gulf Coast vapor drive, tropical storm exposure, and occasional flood events — closed cell spray foam is the correct product for crawl spaces, rim joists, exterior walls, metal building panels, below-grade assemblies, flood-prone areas, oil and gas applications, and any location where vapor control, moisture resistance, or structural performance is a requirement. It is not a budget product. It is the highest-performing insulation product available, used where the performance justifies the cost.
DENSITY AT CURE
- Class II
AT 2" THICKNESS
- 1–2 Days
Frequently Asked Questions
WHICH ONE DOES YOUR PROJECT NEED?
These are two different products used in different locations. The choice is not about which is better overall — it is about which is correct for each specific assembly in your building.
IS CLOSED CELL SPRAY FOAM ACTUALLY WATERPROOF?
Closed cell spray foam resists bulk water intrusion — it does not absorb liquid water the way open cell foam does. The encapsulated cell structure prevents water from entering the foam matrix under normal conditions. FEMA's Technical Bulletin 2 specifically identifies closed cell spray foam as a flood damage-resistant material for applications below the base flood elevation, meaning it can be wetted during a flood event and retain its insulating and structural properties after drying. It is also a Class II vapor retarder at 2 inches — it significantly slows the passage of water vapor through the assembly. It is not identical to a polyethylene vapor barrier in terms of vapor impermeability, but it is the most moisture-resistant insulation product available for real building assemblies.
WHAT IS THE R-VALUE OF CLOSED CELL SPRAY FOAM AND HOW DOES IT COMPARE?
Closed cell spray foam delivers approximately R-6.5 per inch of installed thickness — the highest R-value per inch of any commercially available insulation product. For comparison: open cell spray foam delivers R-3.8 per inch, fiberglass batts deliver R-3.0 to R-3.8 per inch, and blown-in fiberglass delivers R-2.9 to R-3.8 per inch. A 2-inch layer of closed cell foam equals R-13 — matching a full 2x4 stud cavity packed with fiberglass batt insulation, but in half the depth and with vapor retarder and structural performance that fiberglass does not provide. In assemblies where cavity depth is limited — rim joists, metal building panels, below-grade walls — the R-value per inch advantage of closed cell foam is the critical specification factor.
DOES CLOSED CELL FOAM STOP CONDENSATION IN METAL BUILDINGS?
Yes — permanently. Interior condensation in metal buildings happens when warm, humid outdoor air contacts a metal surface cooler than the dew point. In Houston's summer, that dew point is often 74°F or higher. Closed cell spray foam eliminates this by bonding directly to the metal surface and creating a continuous Class II vapor retarder between the humid outdoor air and the cold metal. Once the foam is in place, there is no longer a cold metal surface for humid air to contact — the foam covers every inch of metal it is applied to, including the back side of purlins, girts, and panel seams. The condensation that previously dripped from the ceiling and streaked the walls stops immediately after installation. This is the most common and highest-impact result reported by metal building owners after closed cell foam installation.
HOW MUCH DOES CLOSED CELL SPRAY FOAM COST IN HOUSTON?
Closed cell spray foam installed in Greater Houston typically runs $2.50 to $5.00 per square foot of surface area, depending on thickness, application type, accessibility, and project scope. A standard crawl space encapsulation on a 1,500 square foot pier-and-beam home typically runs $3,500 to $6,500. A 40x60 metal building fully insulated at 2-inch closed cell on roof and walls typically runs $8,000 to $14,000. Barndominium shell applications — exterior panels only — run $6,000 to $12,000 for a typical 40x60 shell, with additional cost for interior open cell finish-out. Closed cell costs approximately 40 to 60 percent more per board foot than open cell foam because the raw materials are denser and more expensive. The cost premium is justified where vapor control, moisture resistance, or maximum R-value in thin spaces is the requirement. Use our free cost estimator for a project-specific ballpark, and ask about 0% interest financing through Wells Fargo for 12 months.
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