Introduction: Garden Retaining Wall -- Plastic Window Screen and Cement
This is a low retaining wall added to the base of a rebar trellis on a hillside to create a terraced area for planting vines.
The trellis is made just by sticking the ends of iron rebar in the ground, and then tie wiring more rebar to it. To make the wall, plastic window screen material is attached to the rebar structure temporarily using clothespins. Then grout, which is stickier than cement, is used to replace the clothespins. Once held to the rebar structure, the screen is plastered with cement and sand, resulting in a thin cement wall about 3/4" thick. It doesn’t have to resist a lot of force. Being thin, less material is used, and the wall is relatively light weight.
Step 1: Defining the Top and Bottom Edges of the Retaining Wall
Two horizontal lines of rebar are added to the trellis, representing the top and bottom edges of the retaining wall. The top edge comes to a little above where ground level will be when the area is filled with fertile soil. The bottom edge is a little bit off the ground. There is no foundation under the wall, although the wall does make contact with the ground in a few places. The weight of it is basically supported by the trellis itself.
Step 2: Temporarily Hold the Screen With Clothespins
The plastic window screen material is cut with a little excess material to fold over the rebar. It is temporarily held in position with clothespins.
Step 3: Clothespins Removed, Grout Adheres the Folded Over Screen Material to the Rebar
Once you get the screen adhered to the rebar, work on individual square areas doesn't affect neighboring squares much, and the plastering goes pretty easily.
Step 4: Plaster One Side With Cement and Sand.
If the wall leans toward one side or the other, it is usually the top side of the wall, that has gravity helping it, that gets plastered first. Plastering the underside of a porous material, like screen, can be difficult because gravity pulls the plaster down, away from the screen, and there is not much surface area of plastic for the cement to stick to. Cement doesn't stick well to air.
On the top side of the screen, gravity helps the cement rest on the screen until it hardens. Plus, the cement that works its way through the screen holes helps it grab onto the screen.
Step 5: Plaster the Other Side
The nearest end of the wall has been plastered on both sides. The far end still needs plastering on this side.
Step 6: Fill the Planter With Topsoil and Compost
Most plants like a good rich soil with lots of nutrients. Topsoil and compost make them happy.
Step 7: Plant Your Vines
At last, time to plant! I planted some passion fruit, chayote, spinach, and some low-growing things along the base of the trellis. By next summer it should be producing food and shade.