How to Build a Timber Retaining Wall

What You'll Need
4x6 inch timbers
Metal rebar rods
Sledge hammer
Wood dowels
Landscape felt

A timber retaining wall is a great landscaping design element that is both functional and attractive. Retaining walls can be used for several different applications from a simple flower bed to leveling off parts of a yard that has sudden drops.

While there are many different types of materials you can use from rocks, to cement, to strong 4x6 timbers. A timber retaining wall, however, gives the landscaping a more rugged look and can blend in very well with the surrounding grounds.

Getting Started

Get started with your timber retaining wall by excavating the area where you are going to build the retaining wall. Dig out the side of a slope until the sides are flat and the ground is level. The grading should also be kept level.

Drive Rebar into Ground

After leveling off the ground then drive metal rebar into the ground about 10 inches every 4 feet. Use the sledge hammer to drive it into the ground. However keep the metal bar as straight as possible. Once you have at least 2 feet of bar still out of the ground, then you can lay down landscaping felt. Then you can also lay down a layer of crushed rock. This should be about 2 inches thick.

Lay First Layer of Timber

Level the bottom side of a 4x6 length of timber with the hand planer. Then drill appropriate holes for the rebar to stick through and slide the timber into place over the rebar rods. Add as many timbers as you need to complete the first layer.

Level, Level, Level

It cannot be stressed enough to continually check this first layer of your timber retaining wall to keep it level. It there is a little deviation here, then the whole wall will be off, and quite noticeable near the top.

Add Each New Layer

Begin building the timber retaining wall up with new layers of timber. There are some things to remember here.

Stagger each new tier - do not simply stack the timbers on top of each other. Stagger the lengths for added strength.
Continually check for level - Always have the level on the retaining wall somewhere. You want to keep it level all the time.
Use dowels to attach timbers - Using a drill and hole saw attachment, drill holes the diameter of 2" to 3" wooden dowels. Drill one hole about 2 1/2 inches deep on the top of a timber beam and another the same depth on the bottom of another beam and connect with the dowel.

Continue building up the tiers of timbers until you reach the top of the area you want to retain.

Back Fill

Carefully fill in the back of the wall with dirt, building it up to the top level of the wall and existing landscaping. Pack it down and plant flowers or grass.