How many cavities does a typical masonry block contain?

A typical masonry block, often referred to as a concrete masonry unit (CMU), usually contains two cavities. These cavities are essential for various reasons, including reducing the weight of the block, improving insulation properties, and allowing for the placement of reinforcing materials like steel bars, which can enhance the strength and stability of the structure.

Having two cavities allows for a more efficient use of materials while still providing structural integrity and energy efficiency. The design of the block facilitates better handling and installation, making it a popular choice in construction. The presence of cavities also provides an opportunity for filling them with insulation or grout to further enhance the thermal and acoustic performance of the wall.