Step 1: Measure the area of your retaining
wall.To do this you will need: - The length of the wall. - The
height at both ends of the wall.This area is simply calculated by length
x height for basic square or rectangle spaces. For odd shapes break your area
down into several sections. For triangular areas use half base x height to
calculate your area.
Step 2: Increase your total area by 10% to allow for
cuts, part blocks & breakages.