A breeze block is a concrete block which has been made with a blend of concrete and ash. Other types of concrete blocks may be used with clinker, sand, or gravel as fillers, but in some regions of the world, concrete blocks are referred to generically as “breeze blocks,” whether or not ash is present. These blocks can be used in a variety of construction projects and tasks.

Concrete masonry units, as they are more formally known, can be made in a variety of densities and weights, depending on the fillers used. High density blocks are utilized in construction to create supportive and load-bearing features such as walls and foundations. Lower density blocks may be used to make garden walls and various other non-structural features, including the famously cheap shelving made from breeze blocks and lengths of wood by college students around the world.

These blocks may also be referred to as foundation, cinder, or cement blocks, regardless as to the fillers used. The term “breeze block” is most commonly used in Great Britain and nations where British English is spoken, as “breeze” is used to mean “ash” or “cinders.” People outside of these regions may refer to breeze blocks as cinder blocks.

The breeze block design is relatively lightweight, making such blocks unsuitable for bearing substantial or heavy loads. The design also means that these blocks also weigh much less than denser blocks, which can make them easier to handle. Typically, breeze blocks have hollow sections which are designed to make them even lighter and easier to work with, and these sections also confer insulating properties on the finished block, because the air in the spaces acts as an excellent insulator.

When breeze blocks are used to build a structure, they are laid in overlapping courses or layers which distribute the weight of the blocks and create a more aesthetically interesting finished structure. The breeze block structure can be cemented together with the use of various mortars, and they may be supported internally with rebar or other supportive stakes and posts which keep the blocks in place, lend structural stability, and increase rigidity.

Many home supply and construction stores carry breeze blocks, usually in classic concrete gray, although specially dyed and prepared blocks are also available. People should be aware that although an individual breeze block is fairly light, a large load can add up to a lot of weight, which can make breeze blocks cumbersome or challenging to handle.