BIG GAP FILLER FOAM SEAL 12OZ

GREAT STUFF PRO Gaps & Cracks Insulating Foam Sealant is a professional gun-grade polyurethane foam designed specifically for air sealing and insulation in larger, irregular voids commonly found in wall and floor assemblies. Unlike lighter-duty straw foams that are intended for small cracks, this formulation is engineered to expand more fully and maintain structure in deeper cavities, making it better suited for substantial gaps where consistent fill and stability are required.

This foam is typically used in openings where air leakage is more significant, such as rim joists, sill plates, top plates, plumbing stacks, electrical chases, HVAC penetrations, and larger framing voids. It is formulated to expand into these spaces and conform to uneven surfaces, allowing it to bridge larger or irregular-shaped gaps that would be difficult to seal effectively with caulk or lower-expansion foams. The controlled expansion helps ensure the material fills the cavity thoroughly while still maintaining predictable behavior during curing.

  Once dispensed with a professional foam gun, the product expands to occupy the full depth of the void, creating a dense, closed-cell structure that bonds tightly to common building materials. This makes it especially effective in larger gaps where structural irregularities or inconsistent framing can leave significant air pathways. After curing, the foam becomes rigid and stable, helping reduce air infiltration, moisture movement, and energy loss across larger sections of the building envelope.

  Because it is designed for larger applications, it is commonly chosen for new construction, major remodeling, and weatherization projects where deeper cavities and broader air leakage points must be addressed in a consistent, durable way. Its gun-grade delivery system also allows for controlled application over extended runs, making it more efficient for filling larger sections compared to consumer straw foams that are limited in output and precision.