Building Stone Walls

There are lots of summer projects available for the gardening enthusiast. You're probably harvesting summer vegetables and enjoying fresh flowers indoors, but this is the time when I start thinking about fall planting. There are many ways of creating new usable space in your yard, but I think one of the most attractive and enduring methods is to create new beds by constructing walls.

Timbers are a good medium for defining space, but I am partial to stone walls. I have an aversion to placing walls where no wall is needed, but walls are great for terracing a hilly backyard, raising a bed around the foundation of your home, leveling ground where it's a little too steep or extending the size of an existing bed.

Construction of new homes today frequently raises foundations slightly from ground level to aid runoff. The slope away from the side of the foundation is sometimes too steep to use as a planting area. This is the perfect spot for a wall.
Building walls is not a difficult task, but it does take some time and planning. The process is the same whether you are extending a bed around the foundation of our house or terracing your steep backyard with a series of walls.

The amount of stone you'll need naturally depends on the size of the wall you are planning to build. For sake of example, you should know that with approximately 1 ton of stone, you can build a wall 1-foot high and between 14-20 feet long.

Simply, the stones should be stacked like bricks - overlapping each other so that there are no vertical seams. Stones should be as flat as possible and 2 inches to 4 inches thick. Even though you are going to look at the edge of the piece, it should be 12 x12 to 12 x 18 inch flat surface so it is heavy enough to stay in place. When building a dry-laid stone wall, never go higher than 36 inches. Once you reach that height, step back into the hillside about three feet and go up again.

When you build the wall, you need to remember several things about soil and water. During the winter, moisture in the soil will expand when it freezes. Therefore, you must use several techniques to avoid the soil's ability to push the stones out and ruin the wall.

A wall should be tiled. Starting slightly below grade level behind the wall, install a perforated tile that will allow for automatic removal of excess water. In addition, gravel should be used behind all walls to aid in water removal. I've seen walls that lasted 30 years and I've also seen walls that have fallen in three. So, don't cut corners on this step.

Start the wall by removing the sod. The first layer of stone should be 1 to 2 courses below grade level. The stone should not be laid absolutely flat, but should be "dipped" slightly, tilting back into the soil. That way gravity helps hold the stone in place. In order to move the stone, the earth would have to push out, up and over at the same time.

Now it's time for the second layer. In addition to dipping the layer of stone back slightly, there is one other technique you should use to keep your wall in place. Instead of placing the second layer flush with the first layer, it should be back from the front edge slightly, approximately one-fourth inch. Each additional layer should be moved back slightly as well. This is called battering and it's one more assurance that your wall will last. (Dipping and battering - almost sounds like we're deep-frying fish, but fishing is my other favorite summer project!)

Here are a few more tips: with a taller wall, you want to use stone up to 4 inches think. A shorter wall is fine with thinner stone, 2 inches to 4 inches; and smaller walls used more for their decorative quality are great for very thin stone - only 1 to 2 inches. With any wall, use the thicker stone on the bottom, thinner stone on top. It's not a physical requirement - it's just aesthetically pleasing.

There are a variety of stones and colors from which to choose. Talk with a stone supplier, letting him or her know what you have in mind and emphasizing longevity. After investing your time and money in a wall, you don't want to have to re-build it. Also, when the stone is delivered, make certain you ask your supplier to dump the stone on your lawn, not your driveway. I've seen lots of stone get broken needlessly when it was dumped on a drive (it's also hard on the driveway) and it may be several days before the driveway could be used.

You can create a beautiful usable space in your landscape with stone walls. It's a rewarding project that will look good for years.