Common Concrete Block Shapes

Since the first concrete block was made, the buildings and foundations of homes and businesses have been constructed with them. Also called "concrete masonry units," or CMUs, concrete blocks are versatile, economical, fire-resistant, energy efficient and low maintenance. The standard block size is 8 inches high by 8 inches wide by 16 inches long. The most common ingredients are cement, water, sand and gravel.

Grey Block

Regular grey blocks are commonly seen rectangular blocks with two core holes that make up many building applications. The actual dimensions for a standard rectangle grey block are 7 5/8 x 7 5/8 x 15 5/8 inches, but blocks are referred to by the dimensions that include one mortar joint. Hence, they are referred to as 8 x 8 x 16 inch blocks. This block is manufactured in varying weight and density classifications and is available in hundreds of sizes. The hollow cores can be filled with insulating materials for energy efficiency.

Split Face

A split face block is a grey block that is intentionally cracked under pressure to produce a stone-like or rough texture by exposing the natural aggregates used in the manufacturing process. Aggregates are the gravels, crushed stones and sands mixed with cement and water to make the concrete, and will vary depending on the local materials available.

Split Rib

The split rib concrete block is also cracked intentionally to expose three to eight ribs, or ridges, for a distinct appearance. These slotted blocks have high sound-absorbing qualities that make them ideal for factories, gymnasiums and other buildings where noise is a consideration.

Brick Block

A brick block is a grey concrete block embossed with a pattern to look like a six-brick staggered running pattern. These units are suitable for construction that is only one block wide or they can be used as a veneer.


Burnished, or polished, concrete blocks are durable and visually pleasing. Textures are smooth and polished, usually with an acrylic coating to reduce maintenance needs. This coating is also mould and graffiti resistant. Burnished blocks come in a variety of colours, shapes, and surface textures and can also be made with recycled materials.

Chimney Block

The chimney block is fire-resistant and comes in 8-inch by 8-inch squares or 8-inch-by 12-inch rectangles. Both sizes come with or without cutouts for flues.

Column Block

This is a concrete sleeve that is used as a wrap or an accent feature. The texture is smooth or burnished. The column is available in 24-inch or 36-inch diameters.

Other Shapes

Other forms of concrete blocks include concrete pavers, grid paving units, interlocking paving units, segmented retaining wall blocks, and roof pavers.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Lynn Star has a BA in Communications, is a 20+ year professional in real estate, tax analysis and preparation, and an in-depth researcher of any topic that catches her interest. She is also an avid do-it-yourselfer in home improvement, crafts and green technologies.