Rat Proofing a Property - Which Entry Points Should You Check?

One: The Drainage

First every time in this area, and it accounts for more of our rat jobs than everything else combined. Lift the inspection chamber cover and look at the benching and the channel for cracks or missing sections. Look for a redundant connection from a removed outside toilet or old extension, capped at the top and open at the drain.

Smear marks inside a chamber mean it is in use. This is also the one you cannot fix yourself — it is a drainage contractor, and sometimes the water company where the run is shared.

Two: Air Bricks and Ground-Level Openings

Walk the whole perimeter, including behind bins, along the side return and behind planters. Look for cracked or missing air bricks, gaps at their edges where mortar has gone, and any that have been rendered over and split.

Then the joint where an extension meets the original brickwork, eroded mortar at ground level, and any gap where the ground has been raised against the wall.

Three: Pipe and Service Entries

The soil pipe where it enters the building, which is usually a rat-sized hole. The gas and water service entries. Waste pipes from a kitchen or utility. Cable entries for the meter and telecoms. And redundant pipework left in place when something was removed.

Check inside as well as out: under the sink, behind the boiler, at the back of the airing cupboard. In a flat, the boxing around the soil stack is the main route between properties.

Four: Doors, Garages and Outbuildings

The gap under a garage door, which is frequently large enough to walk under. Side and back door thresholds with worn or missing seals. The junction between a garage and the house, particularly where there is an internal connecting door.

Sheds and outbuildings matter as harbourage rather than entry — a shed on bearers with a gap beneath it is a nest site a few metres from the house.

Five: Upwards, and What Not to Do

Rats climb. Check where a downpipe passes an open eaves course, the junction where an extension roof meets the main wall, lifted tiles, and any tree or fence that reaches the roofline.

And whatever you find: do not seal it while there is activity inside. Proofing an occupied building traps rats in it, and a rat that dies in a cavity is a considerably worse problem than the one you started with. Treat first — £190 for a flat, £240 for a house — then proof at £180 for up to an hour.