Rodent exclusion that seals Long Beach homes so rats and mice cannot get back inside

Expanding foam is the most common patch we find chewed through. It is soft enough for a rat to gnaw in minutes and it gives no resistance on its own. The same goes for plastic mesh, window screen, wood plugs and caulk by itself.

Rodent-proof materials resist chewing and weather. Galvanized hardware cloth, usually quarter-inch or half-inch mesh, keeps air moving through vents. Sheet metal and flashing cover larger gaps and roof returns. Copper or stainless mesh packed into pipe gaps holds up in salt air better than plain steel wool, which rusts. Foam or sealant can be used as a finish over mesh, never as the barrier itself.

• Galvanized hardware cloth for vents and open framing
• Sheet metal and flashing for roof returns and larger gaps
• Copper or stainless mesh for pipe and wire penetrations
• Rodent-resistant garage door seals and corner guards
• Exterior sealant as a weatherproof finish over metal

Most people check the obvious holes and miss the ones rodents actually use. Roof returns are the biggest: the small open triangle where a lower roof meets a gable wall or where two roof planes meet at an eave. From the ground they look like shadows. From a ladder they are often wide open into the attic.

Other common misses include the gap behind a gutter where the fascia has shrunk, the opening around the air conditioning line set, a dryer vent without a flap, the space where a patio cover attaches to the house and the hole where cable or phone lines were added years after construction. Chimneys with no cap and plumbing vent stacks with gaps at the flashing also let rats drop into walls.

Exclusion is durable, but houses change. Roofers lift tiles, cable installers drill new holes, painters remove vent screens, and plumbers leave gaps around new lines. Any of those can reopen the structure without anyone noticing.

A quick look around the outside of the house twice a year catches most new openings early. Check vents for damage, look for new holes around utilities after any service work, and watch the garage door seal. Keep branches trimmed back from the roof so rats are not tempted to keep testing it. If you hear scratching again, call promptly, because a new entry is much easier to find and close before a population builds.

The Spanish Colonial Revival homes in California Heights, Bixby Knolls and Bluff Park often have clay tile roofs with open channels at the eaves and many roof returns where small towers, arches and additions meet the main roof. Without bird stop or mesh at the tile ends, those channels run straight into the attic. Craftsman bungalows in Rose Park and Belmont Heights have open rafter tails, many foundation vents along a raised floor and decades of patched utility holes.

Salt air near Belmont Shore, Naples and Alamitos Beach corrodes older vent screens and steel wool within a few years, which is why we use galvanized and copper materials. The 1950s ranch homes of Los Altos, Lakewood and El Dorado Park Estates are simpler to seal, though attached garages, AC line penetrations and later patio covers are common weak points. Cliff May Ranchos in the Plaza, with exposed beams that extend beyond the walls, need careful closures where each beam passes through.