How to Tier Retaining Walls
- 1). Set a paver stone onto the ground in front of the hill to mark each end of the wall. Add a buffer zone of about 3 inches on each side of the paver stones, and mark the outline of the wall by driving wooden stakes into the ground or spray-painting the ground.
- 2). Dig a trench between the lines that is 12 inches deep. Level the soil out in the trench and tamp it down to compact it.
- 3). Pour a 4-inch layer of crushed limestone into the trench. Rake it smooth and tamp it down to compact it. Add two more inches of limestone to the trench, level it and tamp it down.
- 4). Set the first paver stone on top of the limestone at the end of the trench. Place a level across the paver, and tap it down with a rubber mallet to level it if necessary.
- 5). Place the second stone next to the first paver. Lay the level across both stones, and tap down on the second stone to make it even with the first paver if necessary.
- 6). Continue laying the first course of stones using this method until it's complete.
- 7). Dig a small trench behind the first trench for a drainage system. Slope the soil in the bottom of the trench toward the area you want the water to drain into, using a slope of about 1 inch for every 100 feet of length.
- 8). Lay landscaping fabric over the soil in the drainage trench to prevent it from clogging the drain tile.
- 9). Cover the landscaping fabric with a layer of drainage aggregate an inch thick.
- 10
Lay the drain tile on top of the drainage aggregate in the drainage trench. This is perforated pipe made of plastic that allows water to flow through it. - 11
Lay the second course of paver stones on top of the first course. Cut a paver in half with a wet saw or hammer and chisel, and place that on the end of the wall to stagger the pavers in the different rows. Apply a thick bead of masonry adhesive on top of the pavers in the first course in a zig-zag pattern. Set the pavers in the second course, staggering the pavers in the first course and setting them about 3/4-inch back from the pavers in the first course to help increase the strength of the wall. - 12
Install the third course of pavers, using the same technique you used to install the second course. Stagger the pavers in the third course from the pavers in the second course. - 13
Dig into the hill behind the wall so the edge of the hill is about 8 inches behind the back of the pavers. Lay landscaping fabric over the bare soil behind the pavers. - 14
Cover the landscaping fabric behind the wall with drainage aggregate. Tamp the aggregate down to compact it. - 15
Continue building the wall until it is three feet high. - 16
Pour drainage aggregate into the gap between the wall and the hill until it's about 3 inches below the top of the wall, and tamp it down. Cover the aggregate by backfilling it with soil. - 17
Dig into the hill on top of the wall, going back 18 to 24 inches from the back of the pavers. - 18
Build a second retaining wall, repeating the steps you followed to build the first wall.
Source...