Rodent proofing & exclusion

Close it before the invasion

Rats, mice, squirrels, raccoons and possums all want the same thing: an easy way in. Rat pressure across this region is getting worse, not better. We inspect the whole building, find every gap, and physically close it — which is the only part of pest control that keeps working after we leave.

(646) 778-9595 4.944 Google reviews

What an open entry point actually looks like

Every photograph below was taken on one of our own inspections. None of it is unusual — this is what most buildings look like once you get down and actually look at the base of the wall.

Daylight visible under a closed steel service door — If you can see daylight under a closed door, a rat can walk under it. This is the single most common opening we find on commercial buildings.

Unsealed conduit and cable penetrations through an exterior stucco wall — Utility and cable penetrations left open after installation. Leaf litter piled against the wall gives cover right up to the opening.

Two drain pipes passing through a large broken hole in a stucco wall — The hole was cut oversized for the pipes and never closed. Everything around the pipe is open wall cavity.

Electrical wiring passing through a hole in a brick wall with a brick missing — Wiring run straight through the brickwork with a whole brick removed and never made good.

A cellar window grate with broken and missing bars at the base of a painted brick wall — A cellar grate with bars broken out, at pavement level. This is a direct route from the street into the basement.

Two open rectangular holes cut into a concrete foundation wall — Openings cut through a foundation wall and left as they were. Rats do not need to gnaw anything here.

What we do about it

Each opening gets closed with a material the animal cannot chew through or push past — steel plate, hardware cloth, and sealant where it belongs. Not expanding foam, and not steel wool on its own.

Pipe and valve penetrations

The same shut-off valves with steel escutcheon plates fitted over the openings — **Before:** Under a kitchen sink: the holes around the shut-off valves open straight into the wall cavity.After: The same valves with steel plates fitted tight around the stems. The route into the cavity is gone.Drag across the photo to compare.

Open gaps in the wall around two shut-off valve stems under a sink — **Before:** Under a kitchen sink: the holes around the shut-off valves open straight into the wall cavity.After: The same valves with steel plates fitted tight around the stems. The route into the cavity is gone.Drag across the photo to compare.

Conduit through a wall

The same conduit with a steel plate and sealant closing the opening — **Before:** A commercial kitchen wall: the hole cut for the conduit is far larger than the conduit itself.After: Closed with a steel plate cut to fit around the conduit, then sealed at the edges.Drag across the photo to compare.

Flexible metal conduit entering an oversized hole in a stainless steel wall panel — **Before:** A commercial kitchen wall: the hole cut for the conduit is far larger than the conduit itself.After: Closed with a steel plate cut to fit around the conduit, then sealed at the edges.Drag across the photo to compare.

Radiator and baseboard cavities

An open cavity beneath a radiator showing exposed floor joists and pipework — Behind a radiator cover: the cavity is open to the joist bay and the rest of the building.

The same radiator cavity with sheet metal fitted to close off the void below — Sheet metal fitted underneath to close the void, with the pipework left serviceable.

Vents, soffits and roof line

Birds and squirrels use the openings you stopped noticing

Dryer vents, bath fan outlets and soffit gaps are the usual routes. If you are not sure what cover to fit, the rule is simple: it has to be something the animal cannot chew through or push aside. We use galvanised hardware cloth screwed down with fender washers, which keeps the vent working while closing the opening.

Book a proofing inspection

Hardware cloth screwed over a wall vent with fender washers — Hardware cloth over a wall vent, fixed with washers so it cannot be pulled away.

A screened vent seen in context on the underside of a painted soffit — The same vent in context. The airflow is unaffected; the access is not.

Building or renovating

The cheapest time to do this is before the walls close

Every new gas line, water line, conduit and vent creates a penetration. On a building site nobody is thinking about rodents, and the openings get covered over rather than closed. Getting them sealed as the work goes in costs a fraction of opening finished walls later — and it is the difference between a building that stays clear and one that has a problem every winter.

A new gas line entering a wall through a steel plate sealed around the pipe — New gas line, sealed at the wall as it was installed.

An open gap in drywall around a newly installed pipe and valve — The same detail left open — what we normally find instead.

Questions about rodent proofing

How small a gap does a mouse actually need?

A mouse gets through a gap about the width of a pencil, and a young rat through one about the size of a quarter. That is why so much of this work happens at pipe penetrations, door sweeps and vents rather than at doors and windows.

Why seal instead of just baiting?

Bait deals with the rodents that are already inside. It does nothing about the opening they used, so the next one walks in through the same gap a week later. Sealing is the part that makes the result last, and it is the step most cheap treatments leave out.

We're renovating. Should we do this now?

Yes, and it is the best time. While walls are open and lines are being run, every new penetration is a potential entry point. Closing them as the work goes in costs a fraction of chasing them afterwards, and you avoid opening finished walls later.

Do you do this for commercial buildings too?

Yes. Restaurants, food service, retail and multi-family buildings are a large part of this work — cellar doors, delivery entrances, utility penetrations and compactor areas are the usual sources.

What about birds and squirrels?

Same principle, different opening. Vents, soffits and roof-line gaps are the usual routes. If you are unsure what cover to install, the important thing is that the opening is closed with something the animal cannot chew or push through — hardware cloth rather than plastic or screen mesh.

Close it before the invasion.

Free rodent proofing inspection and a written estimate across NYC, Long Island and northern New Jersey.

(646) 778-9595 Request an inspection