Rock walls are a beautiful addition to your landscape, and there are several reasons why they are so popular. They define property spaces, improve the functionality of your landscape, and they last a long time, assuming they are built correctly. A poorly built rock wall shifts and slides and causes more problems than solves. To build a rock wall correctly isn’t necessarily an easy job, but it pays off big time over time.
Choosing Materials: Visit any hardware or landscape store and you’ll see the huge variety of materials you can use for a rock wall. You can build the base of wood and wire and then simply cement veneer stones to the wall, or you can use river rock boulders, bricks, paver stones, etc. It’s best to choose stones that have at least one flat surface.
Map Your Course:
Start by marking out the course of the wall. This can be a rope, string, garden hose or unused extension cord. Anything will do, you just need a general line of where you’re going and what you’re doing
Dig It Out:
The best walls have a strong foundation, so you need to dig a trench that is 6 inches deeper than the stones you’re using. Fill it about halfway with gravel, tamping it down so the gravel is compact and level. You really can’t tamp it down enough. When you think you are done, do it a few more minutes to make sure the gravel is completely settled in the soil. Now you’re ready to start stacking stones.
Place the Stones:
Each stone should be touching the ones next to it so they fit nice and snug. You’ll need to trim some stones to ensure they all fit, so have a wet saw available on hand. Use a torpedo level to ensure the stones are level front to back and side to side.
As you layer your stones, use about ½-inch of mortar on top of the rocks. Always do a dry fit first, and then “butter” the rocks with the mortar and put them in place. Some areas may need more than ½-inch of mortar, and that’s OK, just clean off as you do. Keep in mind that wet and clean stones will hold better than dry or dirty ones, so it might be helpful to have a helper available who can clean stones as you need them.
Clean and Dry Time:
Clean all your tools and allow the concrete to dry overnight. It should be dry by morning, but let it cure for a couple of days before putting any stress on the structure.
Note: If you’re building a rock wall to act as a retaining wall, the structure and materials are even more important because the wall must support itself and actively hold back pressure from behind. It needs a solid base, drainage to avoid a build-up of water, and the top tiers should be planned out carefully so they don’t add pressure to the underlying tiers. These types of walls are often left to a professional, especially if they are a critical part of protecting your property.