Spray polyurethane foam (SPF) is the highest-performing insulation available today. It insulates, air seals, and strengthens your building in a single application, dramatically outperforming fiberglass batts, blown-in cellulose, and rigid foam board.
Spray polyurethane foam (SPF) is a two-component insulation system. Component A (isocyanate) and Component B (a polyol resin blend) are stored in separate containers and kept at the correct temperature and pressure before application.
When the two components are pumped through a heated hose and combined in the spray gun's mixing chamber, a rapid chemical reaction occurs. The mixture expands up to 30–100 times its liquid volume and cures into a solid foam within seconds.
Because it expands to fill the space it's applied to, spray foam creates a continuous, gap-free layer of insulation and air barrier. This is its primary advantage over fiberglass batts or blown-in cellulose, which insulate but leave air pathways around and through them.
The end result (open cell or closed cell foam) depends on the specific chemical formulation used. ThermoSeal offers both, in four distinct products engineered for different applications and performance requirements.
Both are spray polyurethane foam, but they have fundamentally different cell structures, densities, R-values, and best applications.
Soft, flexible, vapor-permeable, ideal for interior applications
Dense, rigid, vapor-resistant, for maximum performance and structural benefit
Fiberglass batts and blown-in cellulose insulate, but they don't air seal. That gap in performance is where most energy is lost.
Fiberglass batts have no air barrier properties; air moves freely through and around them. Spray foam expands into every gap, creating a continuous air seal that batts and blown-in insulation simply cannot match. Air infiltration accounts for up to 40% of a home's heating and cooling load.
Fiberglass batts achieve roughly R-3.2 per inch. Closed cell spray foam achieves R-6.5 to R-7.4 per inch, meaning you get more than twice the thermal resistance in the same wall cavity space. In tight construction assemblies, this matters significantly.
Fiberglass batts absorb and retain moisture; once wet, they lose R-value and can become a mold substrate. Closed cell spray foam is impermeable to water vapor and bulk water, protecting the building enclosure from moisture-related damage.
Closed cell spray foam bonds to framing members and adds measurable racking strength. ThermoSeal HFO has been tested to 286 mph wind uplift resistance, a structural benefit that fiberglass insulation doesn't provide.
Blown-in cellulose settles over time, reducing effective R-value. Fiberglass batts compress or absorb moisture and lose performance. Closed cell spray foam is dimensionally stable; it doesn't settle, compress, or degrade, maintaining its rated R-value for the life of the building.
When a building enclosure is properly air-sealed and insulated with spray foam, HVAC energy use can drop by 30–50% compared to traditional insulation assemblies. This means smaller equipment, lower monthly bills, and faster ROI on the installation cost.
Spray foam is used across residential, commercial, and industrial construction, wherever continuous insulation and air sealing matters.
Closed cell foam applied to the underside of roof decking creates a conditioned attic, eliminating duct heat loss and dramatically reducing cooling loads.
Open or closed cell foam fills wall cavities completely (no gaps, no voids), maximizing thermal performance within standard stud spacing.
Spray foam on crawl space walls and rim joists creates a conditioned, moisture-resistant enclosure, eliminating the damp, moldy crawl space problem entirely.
ThermoSeal 5G's NFPA 285 certification makes it suitable for multi-story commercial construction where fire-rated wall assemblies are required by code.
ThermoSeal HFO's 286 mph wind uplift resistance makes it the insulation of choice for coastal construction and hurricane-zone building codes.
One of the most common air leakage pathways in older homes. A thin layer of closed cell foam seals this gap completely, a high-ROI retrofit application.
Spray foam's moisture resistance and high R-value make it ideal for cold storage facilities, agricultural buildings, and temperature-controlled warehouses.
Spray foam can be applied over existing insulation or in existing wall cavities during renovation, improving building performance without full gut renovation.
A professional spray foam installation is a precise, equipment-intensive process that takes one day in most residential applications.
The installer masks off surfaces not being sprayed, confirms ventilation, and sets up proportioning equipment outside or in the truck.
Temperature, moisture content, and surface condition are checked; spray foam won't adhere properly to wet or cold substrates below 40°F.
Closed cell foam is applied in multiple passes of 2–3 inches to manage exotherm (heat of reaction) and build to target thickness.
Open cell foam cures in minutes. Closed cell in seconds. Occupants may re-enter the space after the manufacturer's specified ventilation period, typically 24 hours.
ThermoSeal's complete spray foam lineup covers every application from basic residential open cell to NFPA 285-certified commercial closed cell, all backed by 20+ years of spray foam expertise.
0.5 lb open cell: residential walls, ceilings, attics
0.75 lb open cell: enhanced performance, same applications
2 lb closed cell: attics, exterior, coastal, high-wind
2 lb closed cell: NFPA 285 commercial construction
Everything homeowners, builders, and contractors commonly ask about spray foam insulation.
Whether you're a homeowner, builder, or contractor, we have four distinct spray foam products and a nationwide network of certified installers ready to help.
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