With at least one above-grade course of Mosaic panels installed, you're ready to add drainage. Place ¾-inch clear, free-draining angular aggregate to a minimum depth of 12 inches behind the wall.
Drainage aggregate must be free of fine soil to keep water pressure from building behind the wall face and to ensure that water can drain freely through the aggregate.
For walls over 3 feet tall, place a perforated drainpipe behind the first above-grade course of panels, on 1 to 2 inches of drainage aggregate. The slots or holes in the perforated pipe should be on the BOTTOM of the pipe. The drain pipe should be sloped to provide gravity flow of the collected water.
With the drainpipe laid behind the wall, place more drainage aggregate on top of the drainpipe to a minimum depth of 12 inches behind the wall.
