Air brick covers vs self-closing air bricks

Air bricks are easy to miss, and they're a direct way for floodwater to get under your floor. There are two ways to protect them: covers you put on when a flood is coming, or air bricks that close themselves.

Why air bricks matter

GOV.UK's Environment Agency guidance describes air bricks as bricks with holes that allow air to circulate under or through a property. That airflow is the reason they're there, so any protection has to deal with the flood without stopping the air for good. When floodwater rises above a low air brick, it can pour straight into the space under the floor.

Covers

The Environment Agency's advice includes buying watertight covers to put over your air bricks. The National Flood Forum's Blue Pages directory describes temporary options as covers or inserts that can be quickly fitted before a flood.

• When they work: only once someone has fitted them.
• Effort: you need to be home, get the warning in time, and reach every air brick, including ones behind bins or plants.
• Afterwards: take them off once the flood has passed, so the air can flow again.

Self-closing air bricks

The same guidance suggests replacing air bricks with self-closing air bricks, which close automatically during flooding. Blue Pages calls these permanent solutions that react to water pressure. GOV.UK lists self-closing air bricks among its examples of flood protection products.

• When they work: whenever water reaches them, even if nobody's home.
• Effort: none on the night, but they replace your existing air bricks, so fitting is a building job.
• Ventilation: they let air through until water closes them.

Compared on: effort, when they work and ventilation

	Covers	Self-closing air bricks
Needs someone home	Yes	No
Works if the warning comes late	Only if fitted in time	Yes
Fitting	Fixings or a frame, then fitted by you before a flood	Replaces the air brick
Air flow day to day	Normal, once covers are off	Normal until water closes them

What to measure

• How many air brick openings your home has, on every wall, and how high each sits above the ground. (Our planner, above, asks for this count.)
• Each one's size, and whether it's a standard brick size or something older or unusual.
• The wall around it: covers need a sound, flat face to seal against.

Certification

Natural Resources Wales advises choosing BSI Kitemark certified products, and SEPA says to look for the Kitemark or equivalent. Air bricks are among the building products covered by BS 851188-1.

FAQs

Can I just fill my air bricks in?

Don't do that without advice. Air bricks are there to let air circulate under or through the house, so ask a surveyor or builder before changing them.

Where do I find suppliers?

The National Flood Forum's Blue Pages lists them, without endorsing any.