Class A bricks offer higher compressive strength and lower water absorption compared with Class B bricks, making them suitable for the most demanding structural or moisture prone areas.
Engineering Bricks for Wet, Load Bearing and Ground Contact Builds
Engineering bricks are dense clay units designed for strength and low water absorption. They are commonly available in smooth red, blue or grey finishes and supplied in standard cavity wall dimensions. These bricks are often selected for areas exposed to persistent moisture or load, such as retaining walls, foundations, manholes and below a damp proof course. Many products follow widely recognised performance classifications, including compressive strength ranges and water absorption limits, giving predictable behaviour in structural and wet environments.
In use, engineering bricks pair well with general masonry mortars, usually mixed to a structural grade suitable for ground contact brickwork. Where the masonry continues upward, the brickwork can be stabilised with Wall Ties to maintain the cavity structure. At moisture sensitive points, engineering bricks work effectively alongside Damp Proof Course, with some builds incorporating multiple courses of dense bricks as part of a rigid barrier. For changes in height or load distribution, they are frequently used in combination with Concrete Blocks and levelled using standard Cement & Mortar mixes.
Because of their dense composition, these bricks offer reliable resistance to repeated wetting and freezing, making them a dependable choice for areas exposed to harsh weather. They differ from facing bricks, which focus on visual uniformity rather than measurable structural performance. Where high temperatures are involved, such as pizza ovens or fireboxes, engineering bricks are not suitable, and specialist fire bricks with appropriate refractory mortar should be used. When cuts are required on site, a diamond blade angle grinder or bench saw gives the most accurate and tidy results.
Engineering Bricks FAQ's
Yes. They are often used below the DPC, and in some designs, multiple courses of dense bricks can serve as a rigid DPC layer when specified.
An M6 grade or similar structural masonry mortar is commonly used for work at or below ground level; the final mix should match the project’s exposure and design requirements.
Most engineering bricks are manufactured to withstand repeated freeze thaw cycles, making them suitable for retaining walls, ground contact work and exposed locations.
Engineering bricks focus on measurable performance strength and low absorption while facing bricks prioritise consistent colour and appearance.