Why Foam Alone Fails
Expanding foam sealant is commonly used in DIY exclusion attempts — and it consistently fails. Rodents gnaw through foam within hours. The same applies to standard caulk, steel wool used alone (it rusts and compresses over time), and plastic vent covers. Effective rodent exclusion requires materials that rodents physically cannot gnaw through: galvanized metal, copper mesh, and concrete/mortar for below-grade gaps.
Common Entry Points in Miami Homes
Open soffit returns, gaps at roof-fascia junction, damaged roof vent screens, ridge cap gaps, and gaps around pipe boots on the roof. Miami's older housing stock often has significant roofline gaps. Sealed with galvanized hardware cloth and metal flashing.
Tree limbs within 3 feet of the roofline are bridges for roof rats. Trimming back tree limbs is a critical component of roof rat exclusion and is included in our exclusion recommendations.
Gaps around plumbing pipes (under sinks and through exterior walls), electrical and cable conduit penetrations, gas line entry points, and HVAC duct penetrations. Sealed with copper mesh packed into the gap, covered with weather-resistant sealant.
Cracks in CBS block, weep holes, gaps at sill plate, and floor drain covers are Norway rat entry routes. Sealed with concrete mortar, galvanized hardware cloth, or steel-reinforced sealant depending on gap type.
Worn door sweeps, gaps at garage door corners, and gaps between pedestrian door frames and CBS construction are sealed with new door sweeps, galvanized threshold plates, and appropriate gap-filling materials.