How Do I Calculate How Much Gravel I Need For A Brick Paver Patio?

A new brick paver patio is a great addition to a home, and it's surprisingly easy to install using a base of sand and gravel instead of setting each brick with mortar. This method also allows you to quickly and easily replace bricks that are damaged. You'll want to make sure you know how much gravel you need for a brick paver patio before you start installation.

Use a measuring tape to find the length and width of the proposed patio, and multiply the two figures to find the square footage. For example, if the planned patio is 10-by-12 feet, it is 120-square feet.

For circular brick paver patios, measure the radius (the distance from the center to the edge) and use the formula 3.14 _r^2 to find the square feet. For example, if the patio is to be 12-feet across, the radius is 6 feet, so you have 3.14_6^2 = 113 square feet.

Normally you want a base layer of gravel about 4-inches deep. Four inches is one-third of a foot, so multiply the square footage by one-third to find the cubic feet of gravel you need. For a 120-square foot patio that works out to 40-cubic feet of gravel. However, gravel is usually sold by the cubic yard. To find the number of cubic yards, divide the cubic feet by 27. In our example, this is 40/27, or about 1.5 cubic yards. You should add about 5 percent to allow for spillage and adjustments.

Along with the gravel you will need sand. A layer of about 1 inch over the gravel is about right. However, some of the sand will sift down into the gravel. Allow about a third as much in cubic volume for sand as you buy of gravel. For 1.5 cubic yards of gravel, get about one-half cubic yards of sand.

Brick pavers are most often 4-by-8 inches. This works out to 4.5 bricks per square foot, so you'll need about 540 bricks for a 120-square foot patio. Add about 5 to 10 percent to allow for breakage and to keep a few for replacements.