A layered brick garden wall can add a degree of interest to your landscape design. It is useful if you want to raise the soil level in your garden or if you need to balance a sloped yard. Installing the brick wall is pretty straightforward and can be done in a matter of one week, depending on the size of the wall you want to build.
Mark out your wall with some string and stakes and then pour a line of sand along the line. A two-brick-thick wall is much stronger than a single brick garden wall and can serve as a place to sit while gardening, so mark out the width of the wall to be about 18 inches wide as well as the length of your garden. Remove the dirt so that you have a trench about eight inches deep under the area where you plan to build your brick wall.
Set your foundation. Mix your concrete with five parts of sand and enough water to moisten the mix so that it is like a thick pudding. You will have about two hours to work with it before it hardens, so work quickly. Fill in your trench with the wet mixture. Before it sets, pull a two-by-four over it to level it out. Allow it to dry for three or four days.
Mix up a new batch of concrete with the 5 parts of sand and lay a one inch layer on the prepared foundation. Place a good dab of concrete on the tops and sides of your bricks, smooth it out and then set them in place. You can use whatever pattern you like, just keep the joints alternating so the wall doesn't have a weak point. Scrape off any excess concrete that squeezes out between the bricks before it sets. Keep the joints about 3/8 inch thick.
Allow the wall to set for three or four days before throwing dirt up against it or sitting on it. This wall will be strong enough to last for years, if you didn't build it too high. Walls higher than three feet will need a deeper foundation and pipes for draining ground water, as well as reinforcement in the concrete.