Which brand spray foam for cracks and pipes?

Contractors and builders standardly use DuPont Great Stuff Pro Gaps & Cracks or DAP Touch ’n Seal closed-cell polyurethane expanding foam to reliably seal pipe penetrations and structural gaps against air infiltration. We recommend using this as well.

Unsealed pipe penetrations, rim joists, and foundation gaps account for significant convective heat loss and moisture transport into conditioned building envelopes. According to the U.S. Department of Energy (2023), air sealing penetrations around plumbing and mechanical chases reduces household heating and cooling loads by up to 15 percent.

If you only do one thing: Choose a gun-dispensed, closed-cell polyurethane foam with controlled low-expansion properties to seal around plumbing pipes without distorting lines or trapping ambient moisture.

• DuPont Great Stuff Pro Gaps & Cracks: Formulated for gaps up to 3 inches (76 mm) wide, this gun-applied closed-cell foam cures tack-free in 15 minutes, fully sets within 1 hour, and delivers an insulating performance of R-4 to R-5 per inch.
• DAP Touch ’n Seal Gun Foam II: Provides a high-density, closed-cell polyurethane seal with minimal expansion pressure, making it ideal for tight annular gaps around copper lines, PVC drain stacks, and PEX water lines.
• DuPont Froth-Pak 210 / 620: Suited for multi-pipe penetrations, rim joist air sealing, and wall-to-foundation transitions wider than 3 inches, this two-component kit expands and cures within 60 seconds with an R-value of R-6.2 per inch.
• Loctite Tite Foam: Built with four times higher cell density and UV resistance than standard retail foams, giving it elasticity to handle the thermal expansion and mechanical vibration common to hot water lines and drain pipes.
• 3M Fire Block Foam or Great Stuff Fireblock: Tested to ASTM E84 and required under IRC Section R302.11 for pipe and electrical penetrations passing through floor plates, ceiling assemblies, and stud cavities.

• Watch out for: High-expansion open-cell foams around flexible PEX tubing or thin-wall drain pipes, where uncontrolled curing pressure can deform plumbing runs or crack fittings.
• Watch out for: Installing single-component polyurethane foams on dusty, greasy, or frozen substrates below 40°F (4°C), which leads to adhesion failure, incomplete chemical curing, and persistent air leakage.
• Watch out for: Leaving exposed polyurethane spray foam unprotected against direct sunlight or interior spaces without a required 15-minute thermal barrier like 1/2-inch drywall.

Measure the clearance around the pipe penetration and select a professional dispensing gun with a closed-cell single-component can for gaps under 3 inches.

General information only, not medical advice. Decisions about health, treatment or wellbeing should be made with a doctor or other qualified healthcare professional.