Rodent Proofing Services in the Bay Area

Everything You Need to Know About Rodent Proofing

Rodent proofing, sometimes called exclusion, is the work of closing every opening a rat or mouse could use to get inside. It sounds simple, but the openings are small and often hidden. A house mouse can typically squeeze through a gap about a quarter inch wide, and a young rat through one around half an inch. That means a loose vent screen, a gap beside a gas line, or a corner where the fascia has pulled away can each be a doorway. Proofing is about finding all of them, not just the obvious one.

Bay Area homes tend to share a few weak spots. Older houses on raised foundations often have crawl space vents with rusted or missing screens. Gable vents and roof vents can lose their screening to weather or to rodents working at the edges. Where a roof meets a second-story wall, small gaps often open up as framing settles. Utility penetrations are another frequent culprit, since the holes cut for plumbing, cable, and air conditioning line sets are rarely sealed tightly. On many homes, the space under the garage door is the easiest way in of all.

Good exclusion work relies on materials rodents can't easily chew through. Galvanized hardware cloth and steel mesh are commonly used over vents and larger openings, while metal flashing is typically used to close gaps along rooflines and corners. Sealants and caulk have a place, but on their own they usually aren't enough, because rats can gnaw through soft materials like expanding foam. The aim is a seal that holds up to weather, keeps vents breathing, and leaves no weak edge for a determined rodent to work on.

Sealing and removal have to go together. Close up a house with rodents still inside and they will chew new exits or die in the walls; trap them without sealing and new ones simply move in through the same gaps. We handle rodent proofing with our own in-house crew, not subcontractors, starting with a free inspection. We clear any rodents still inside before closing the last openings, then repair the damage they left, including replacing contaminated insulation where needed.

Roof Rats, Norway Rats, and Mice: How Each One Gets In

Roof rats are the climbers. They are slender and agile, comfortable traveling along fences, power lines, and tree branches, which is how they usually reach an attic. In the Bay Area they are drawn to backyard fruit trees, citrus especially, and to dense ivy, which gives them cover and a place to nest. When roof rats are the problem, the entry points are typically high: roof vents, gaps at the eaves, and openings where branches touch or hang over the roof.

Norway rats are heavier, stronger, and less inclined to climb. They tend to burrow, so they usually come in at ground level, through foundation vents, gaps around pipes entering the crawl space, holes in garage walls, or the space beneath doors. Signs of Norway rats more often show up in crawl spaces and basements than in attics. Proofing against them means paying close attention to the foundation line, including spots where soil or landscaping is piled right against the house.

Mice can come in almost anywhere, because the openings they need are so small. Gaps around utility lines, dryer vents, weatherstripping, and door thresholds are common routes, and once inside they tend to follow wiring and plumbing runs through the walls. Deer mice, found more often near open land and wooded edges, are a particular concern because they can carry hantavirus. Whatever the species, exclusion only works when every opening is closed, since a single gap left behind becomes the route they all use.

Other Services Homeowners Ask About

Most projects involve more than one service. These are the ones our Bay Area crews pair with this work most often:

• Bay Area rodent removal
• attic cleaning and cleanup
• attic insulation removal and replacement
• crawl space cleaning

We do rodent proofing across the Bay Area from four offices, on the Mid-Peninsula, in the South Bay and East Bay, and in the North Bay, San Francisco and Oakland.