*Quick, Cheap and Durable Retaining Walls*
By: Centurion

The situation arises from time to time where you need a retaining wall which is both quick to build and inexpensive, yet is extremely durable and not simply a temporary fix. I had a situation recently where I needed to build a retaining wall that was strong and permanent, but easy to build because I needed to stop a ditch from eroding. This wall would never be seen, so I didn’t want to spend a lot of money or time building it. My next door neighbor owns a landscape company, so I casually pitched him the question. The article which follows is his advice and my experience using this extremely simple yet very effective wall.

Concrete Bag Wall.
His suggestion, simply put, was to build the wall out of concrete bags. The bags are used as bricks to build the wall. Their naturally uneven shape actually works to hold the wall together while still allowing water to drain through the cracks. It is extremely strong, and being made of concrete, has a very long lifespan.

As far as costs are concerned, the local home improvement store (Home Depot, Lowes, etc.) sells concrete in 60 pound bags for about $1.70 each, but can be found on sale as cheap as $1.25.

Wall Building Process.
1. Roughly level the area where the wall will go, using a shovel. It doesn’t have to be perfect. If you even consider pulling out a four foot construction level, you’re over analyzing the entire process.

2. Go purchase as many bags of concrete as you think you’ll need, then throw in an extra 5-10 bags. You can always use an extra bag of concrete around the house somewhere. I did my estimation by looking at the pallets of concrete at the store, then determined how many bags it took to cover the three foot length of the pallet. The height of a single bag when compressed can also be figured out here.

3. Drop the bags on the area that you leveled (end to end) to make the first row (called the first course). Very important… Leave the concrete in the bags. Make sure the bags are straight and fairly level.

4. Lay the second course of bags on top of the first, but stagger the seams. So a bag on the second row overlaps the gap on the first row below it. Look at the way most brick walls are built. The wall should very gradually lean back into the hill. I usually move back about a half inch to an inch per row. This lean will give the wall strength when you backfill dirt against it.

5. After laying about four or five rows of bags like this, take a break and go get the water hose.

6. Spray the wall down with water until all the bags are soaked, then spray it for another 10 minutes to make sure you get plenty of water. The wall cannot be too wet. The water will saturate the paper bags and allow the concrete to begin to setup and get hard.

Sound easy? It is.

If you want the wall to be higher, it is best to allow the wall to sit for 24-48 hours, soaking it with water once per day to keep the bags wet. (Maybe twice per day during the heat of summer.) After a couple of days, you can begin to backfill the dirt behind the wall, then add more rows to the top as necessary, following the same procedure as before.

According to my landscape guy/neighbor, the bags work well because they will naturally "lock together" as they harden as each bag will conform to the bags above and below them. After about a month (once the concrete is very hard), you can go out and tear the paper off the bags or simply let the paper rot away, which takes about 6 months without assistance.

Drainage and Strength
The wall will naturally drain water because the spaces between the bags allow water through. However, what you have built is actually a 12 inch thick concrete wall, which is incredibly strong. Once mine wall set up and was backfilled, I accidentally drove my truck along the top (too close to the edge) but it never moved.

How does it look?
Very natural. The concrete is a dark gray color and has nice, smooth, rounded edges. It looks like smooth river rock that has been stacked into a wall. Once the wall is finished and the paper is removed, you can purchase some moss and/or ivy and a little potting soil to cram into the cracks to disguise the wall even more. With such a porous surface, moss and ivy will easily take hold and quickly cover the entire wall.

Personal experience…
Quick, Cheap and Easy to Construct.
I built a four foot high, forty foot long retaining wall for approximately $100. I did the entire project alone, and it only took three or four hours of total work time, spread out over a couple of weekends. That was six months ago and the wall has required zero maintenance since then. I don’t expect to ever have to do anything to it again.

Other uses.
- Ever want to build a permanent foxhole or listen/observation post?
- What about a wall for your rifle range to practice "firing from cover"?
- Do you have a two or three foot ditch that is carrying your property down stream? Line it with a natural looking concrete wall…and forget about it.

All materials at this site not otherwise credited are Copyright © 1996 - 2001 Trip Williams. All rights reserved. May be reproduced for personal use only. Use of any material contained herein is subject to stated terms or written permission.