Concrete Block Sizes – What Are The Different Dimensions?

concrete block sizes

The durable structure and variety of appearances of the concrete masonry make them one of the most innovative building products. A variety of textures, patterns, and colors can be achieved by combining different CMUs within the same wall. Specific sizes and shapes of CMUs are contemplating standard, while others are accessible to particular regions. Read this article to understand concrete block sizes.

Concrete Block Dimensions, Size, and Shapes:

CMUs are manufactured in a variety of sizes. You need to understand the fundamental dimensions of the CMUs to begin your first project with the batch of the CMUs. The actual measurement and the width of the mortar joint make the nominal dimension of a CMU. Mortar joints of CMU are typically 3/8″. The other construction materials follow the nominal dimension within a 4″ grid.

Usually, little faces of CMUs are 8 inches by 16 inches, accessible in a nominal thickness of 4, 6, 8, 10, 12,14, and 16 inches. For planning the bond patterns and modular layout according to door and window openings, nominal dimensions refer to the module size. To maintain the four or 8-inch module with 8-inch mortar joints, three dimensions of CMUs usually are 8 inches less than nominal dimensions. For different sizes of CMUs ASTM C90 have the least face shell and web thickness. Generally, unit dimensions are authorized to vary one by ± / inch from specified measurements. ASTM C90 defines the difference between hollow and solid CMUs. A solid unit has at least 75% of the net cross-sectional area if the substantial size of the brick does not surpass 25% of the total cross-sectional area then concrete brick maybe 100% cored.

An infinite amount of CMU shapes are available which allow unique construction properties:

  • Kerf allows easy cutting.
  • Open End allows for vertical strength.
  • Double Open End allows for sheer strength.
  • Bond Beam allows for horizontal strengthen.
  • Knockout Bond Beam allows mason to locate horizontal strengthen.
  • U Lintel allows horizontal to maintain.
  • Sash allows to control joint or door/window frame.
  • Bullnose has a radiused corner.
  • Scored has the number of scores varies.
  • Ribbed has the number of ribs that vary.
  • A column with Pilaster has various sizes.

Why Concrete Blocks?

Concrete blocks are hollow yet rigid, which keeps the wall more stable because of the minimum weight of the bricks. Almost 50% of the block’s total volume has hollow cores, height and depth can be added in outdoor areas using a concrete block wall. When the wall is installed, the reinforcement bar can still be placed within the core of the block to strengthen the structure, because of the concrete block design.


Comparatively, concrete blocks are relatively inexpensive; their cost varies according to the type of block. They have durable material that holds up well in most climates; also, a variety of textures, patterns, and colors can be achieved by combining different CMUs, which makes the concrete one of the most versatile products.

That sums up concrete block sizes!

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