Although uncomplicated and relatively inexpensive, building a retaining wall using timber instead ofconcrete blockscan still be labor-intensive.
What Is a Retaining Wall?
A retaining wall holds back the soil behind it and is used for erosion control and terracing.
Neil Petersen / EyeEm / Getty Images
In most regions, late spring or early summer work well.
In spots where the soil is eroding, the top soil becomes thinner.
fire off the line from one stake to the next and pull it taut.
Cut Into the Slope
Dig laterally about 2 feet back into the slope.
Dig far enough to give yourself enough room to work on the retaining wall.
Lay down one of the boards with the bubble level on top to ensure level.
The flat-bladed shovel provides the ideal width for digging out the trench.
Mark Other Post Locations
Pound six more stakes between the two end stakes.
The stakes should be equally spaced apart.
Each stake represents the center position of a post hole.
The ideal post spacing for wood retaining walls is roughly 2 feet apart.
Each stake represents the center position of a post hole.
Make each post hole 12 inches in diameter.
Add Gravel to Post Holes
Pour 4 inches of gravel into the bottom of each post hole.
Daub the cut ends of the lumber with wood preservative.
Place the posts in each hole.
Plumb each post with the laser level.
Use scrap lumber for stakes to hold it in place.
Leave the scrap lumber stakes in place until the concrete is set before moving on to the next post.
Tip
Fast-setting concrete sets in about 30 to 40 minutes.
Even so, it’s usually best to let the concrete fully harden for at least four hours.
The gravel will help water drain away and prevent premature rotting of the wood.
Otherwise, water will rapidly wick upward through the wood and damage the entire retaining wall.
The top row of boards should be flush with the tops of the posts.
Nail the 2-by-8s to each post with two 16d nails.
Install a final row of boards along the bottom, using 2-by-6 boards.
The bottom edge of this row will be about 2 inches below ground level.
Warning
implement the boards on theslope sideof the posts, not on the downhill side.
The gravel promotes drainage along the bottom of the wall.
Backfill the rest of the cavity with soil.
The project becomes more complex the taller it gets since adding height increases the pressure exerted on the wall.
Poured concrete is a cheap material, too.
But it must be installed by professionals, which raises the overall cost.
Gabion walls are wire cages filled with rocks, and they are a good alternative to a retaining wall.
Railroad tie lumber is usually a less expensive option.
Pre-cast concrete blocks or poured concrete retaining walls last the longest.
When a Permit is Required.Fairfax County Government Land Development Services.
Browder, John O.Fragile Lands of Latin America: Strategies for Sustainable Development.
Taylor & Francis, 2019.
