How Many Cover Blocks Do I Need? A Simple Guide

Before you order cover blocks, you need a count. Here is a simple way to work it out.

For a slab or footing

1. Choose the gap between blocks. Many sites use a gap of about 2 to 3 feet. Ask your engineer.
2. Count rows: divide the length by the gap, then add 1.
3. Count blocks in each row: divide the width by the gap, then add 1.
4. Multiply rows by blocks in each row.

Example: a slab of 30 ft by 20 ft with a 2.5 ft gap. Rows = 30 ÷ 2.5 + 1 = 13. Blocks in a row = 20 ÷ 2.5 + 1 = 9. Total = 13 × 9 = 117 blocks.

For a beam or column

1. Divide the length (or height) by the gap, then add 1. This gives the number of points.
2. Multiply by the blocks at each point. For example, a column often needs one block on each side.
3. Multiply by the number of beams or columns.

Add a little extra

Some blocks break while moving them around the site. So add a small extra, like 5%.

The easy way

Our free cover block calculator does all of this for you. Enter the size, and it shows the count. Then you can send it to us on WhatsApp for a price.