What Is an Air Brick?

Air bricks are masonry products used in homes and commercial buildings. Unlike standard bricks, air bricks have holes in them. They're used for projects that require ventilation. Choosing the right air brick is essential for the success of your project.

Air bricks can be purchased at home supply stores, hardware stores or online.

Despite the holes, they're a sturdy and resilient building material.

Air Brick

Air bricks are often mixed with standard masonry bricks and blend with the surrounding surface, save for the ventilation holes. Standard air bricks are punctured with many circular holes. The wide face of the brick has multiple holes, less than an inch apart, all the way through from one side to the other. You can also buy air bricks in non-standard shapes, like squares, and sizes to fit any project.


Air bricks are primarily used to ventilate foundations where the first floor is wood over soil. In cold weather when the temperature of the home is higher than the temperature of the soil, condensation can collect on the underside of wood flooring, leading to rot. Air bricks allow air to circulate under the floor and reduce the possibility of damage. Normal brick foundations above soil crawl spaces without ventilation holes do not allow adequate circulation. Read any documentation you have from the manufacturer of your home or ventilation system to determine what type of air bricks you should use in your building project.

Other Materials

Some air bricks are actually made of metal. They're still called air bricks because they serve the same function as normal air bricks and because they're shaped and sized the same way. Many specialized air bricks have decorative holes cut into them--this is especially true of cast iron and other metal air bricks.You can also buy plastic or terra-cotta air bricks. Determine what's best for your project before you purchase.


Inserting an air brick into your project is as simple as creating a hole in the wall of the foundation and inserting an air brick. While air brick sizes vary, a standard 9- by 3-inch brick is fine for most projects. It is crucially important to keep the air brick from being blocked. A blocked air brick encourages just as much rot as a regular brick. You can include a vent screen when you install the air brick to help keep debris from filling the holes. If you notice a draft in your home after installing the air bricks, it may be from air flow under your floorboards. Try closing any vents in your home and placing rugs on the floor or additional insulation between the floor joists.