How to Build a Brick or Stone Retaining Wall
A retaining wall holds back soil, either in a planting bed or on a slope or hillside. It can be built out of anything - from stone to wood to poured concrete - and it can significantly alter the contours of your yard or garden. These guidelines cover a low, unreinforced stone or brick wall. For anything stronger, you'll need a contractor.
2. Decide on your building material - brick gives a formal elegance and stone a European air. Don't forget to check out the ever-increasing options in interlocking blocks available at home improvement and do-it-yourself stores.
3. Use a trowel, shovel or grub axe to chop out the cut (a combination of ditch and ledge) where your wall will start.
4. Pile the brick or stone so that it leans inward slightly (to counterbalance the weight of the soil that will be behind it) and use the soil to pack around the bottom layer. If you're using stone, use the biggest ones on the bottom and then pick and choose, fitting them together like puzzle pieces to build stability into the wall.
5. Backfill with soil.
For low walls like these, you can usually get away with a dry-laid wall (no mortar). For added stability, use 1/2 inch of mortar between bricks (more between stones) and allow to dry and cure for a week before backfilling.
If your yard's got drainage problems, you're probably best off consulting a contractor. Whatever you do, make sure water doesn't drain toward the foundation of your house.
A retaining wall is like a dam: The higher the wall and the heavier the soil behind it, the greater the pressure on the wall. Most retaining walls over 3 feet (2 feet in some areas) are thus subject to some kind of permit process; this is taken more seriously in areas of seismic activity, where walls must be able to withstand shock loads in addition to everything else. Check your local regulations before you start.
Article from: www.ehow.com