Why Do We Provide Holes In Concrete Block?

The openings are called “cells” and one reason they are there is because they make the blocks lighter and easier for a mason to handle. But the primary purpose of the cells is that they align from top to bottom of the wall when laid, and enable a builder to fill some cells with grout/concrete to strengthen the wall. It is often done at sides of larger window and door openings, and vertical steel reinforcing bars are added.

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