How to Calculate the Wall Batter on Retaining Walls

The amount of slope that a retaining wall has as expressed in its variance from the true vertical is referred to as its batter. Standard batter, or "cant" as it is sometimes known, is 1 inch of set back or slant per 12 inches of vertical height. For irregularly shaped building materials such as natural stone, the batter can be as much as 2 to 3 inches of slant per 12 inches of vertical height. Calculate proper batter to allow for a more structurally sound and stable wall which will resist the forces of ground heaving and pressure from behind.

A proper slope is critical for retaining wall constructed without mortar.

Step 1

For smaller stakes, a mallet or hammer will suffice.

Drive a stake or rod at the base of the retaining wall. Set it deep enough that it will remain vertical on its own.

Step 2

Make sure level is accurate by testing on a known vertical post.

Level the stake on all sides. Put the level flush against the side of the stake to confirm that it is truly vertical. Adjust as necessary to make it so.

Step 3

A yardstick will work in the absence of a tape measure.

Mark 1 foot from the base on the stake with a marker. Make sure to hold the tape measure tight against the stake when measuring.

Step 4

Almost any type of twine, string or line will work.

Tie a string or line to the stake at the one foot mark. Attach a line level to it if you have one.

Step 5

Hold the string level to the face of the wall. Measure the distance of the string between the stake and the point on the wall where the string is level. This is your batter ratio. For example, if the string is 2 inches between wall and stake, your batter ratio is 2:12, or 1:6.

Step 6

Add up the sum of the string distances, and divide by the number of vertical feet.

Continue the steps as necessary up the stake at 1 foot intervals. The batter may vary, so you may want to get an average.