Rodent Air Brick Covers

An air brick is a deliberate hole in your external wall, and the slots in most older ones are wide enough for a mouse - which gets through a gap of around 5mm, roughly a pencil's width - and often for a rat at around 15mm. It is one of the most commonly missed entry points, because people check doors and pipework and walk straight past the vents.

No. These covers use a fine mesh that lets air pass while closing the gap to rodents and crawling insects. That matters: air bricks ventilate the underfloor void, and blocking one properly - with cement or a solid plate - risks damp and rot in the joists. Mesh is the correct fix, not filling the vent in.

Measure your air brick itself, not the opening in the brickwork, and check the measurement against the size stated on the product page before ordering. Air bricks come in more than one standard size, and older or rendered walls throw up odd ones, so it is worth taking a tape to it rather than assuming.

Yes - these are a screw-fix job on a flat brick face, and no different from putting up a shelf bracket. Fit them from outside. If an air brick is above head height or on an upper floor, use appropriate access equipment or get help; the fitting is easy, the ladder work is what causes accidents.

Only to appearance. Choose whichever blends better with your brickwork or render - the mesh and the fixing are the same either way.

Only through that vent. An air brick cover closes one route, and rodents will use whatever else is open - gaps under doors, holes where pipes and cables enter, damaged drains. Work round the whole building with proofing products rather than fixing one point, and clear anything already inside with traps first - sealing a building with rodents in it just shuts them in.

The mesh is fine enough to stop crawling insects using the vent as a route in, which is a useful side effect if you get woodlice or spiders coming up through the underfloor void. It won't affect flying insects elsewhere in the building.