Although there are many types of material that you can build a retaining wall from, timber is one material that is always beautiful, plentiful and easy to handle. So building a timber retaining wall is probably one of the easiest of the various kinds of retaining walls to build.
When choosing your lumber for your timber retaining wall, make sure that it is pressure treated lumber and is at least 5×6 to ensure it is strong enough to retain the weight of the earth it will be holding.
Here are the major steps for building your timber retaining wall:
Creating the Space – You will need to create a base that you will build your timber retaining wall into by digging a trench about 2 to 3 feet from the hillside you will be retaining, about 12 inches deep. Make sure it is level and add six inches of gravel subbase.
Constructing the Wall – Once you have leveled your first timber to ensure it is even, add your second row. Make sure that the ends of each row are not aligned and that each row is about ½” set back from the one below it. You should use either galvanized spikes or reinforcement bars to anchor the ends of each row of the timber retaining wall to the row beneath it and every three feet along the wall. Install a deadman (a t-shaped horizontal anchor that holds the wall to the soil) every four to eight feet, depending on the length of your wall at about every third row in your wall.
Completing the Wall – Once you have built your timber retaining wall (no more than three feet high) then you will need to backfill the space behind the wall. You begin by putting four to six inches of gravel for drainage (very vital). Add a six inch perforated drainpipe that will drain the excess water to an area at least six inches from the wall. Add more gravel on top of that and continue to add more gravel as each level of the wall is built. When you have completed your wall, you should have a six inch space behind your wall. Fold landscape fabric over the gravel and fill with soil for the last six inches until level with your top of the wall.
After all of this, just add whatever groundcover or flowers you would like to the top and enjoy your efforts. Oh- and don’t forget to boast to your neighbors how you made this beautiful timber retaining wall yourself!