Asked on Mar 31, 2012

Concrete bag retaining wall

Vicki T
by Vicki T
I want to put a short retaining wall to level off the slope to my front yard. Then add fill and finally xeroscaping it to save water. Right now when I water the lawn it all runs down the slope into the street. Not wanting to waste water and also save some money I decided to even out the lawn. My cousin has read about a process of taking unopened bags of concrete layered like bricks to make a retaining wall. I can not imagine it would be a 'pretty' look to my curb appeal. As I sit on a corner lot this wall would be about three feet high and have to go around the corner. She says you soak them down getting them all super wet then water them for another ten minutes. Then after the bags sit and cure for a month I can remove the paper...not so sure I could live with that look for a month! This is supposed to simulate a stone fence. Has anyone had any experience in this?
  11 answers
  • Douglas Hunt Douglas Hunt on Apr 01, 2012
    Vicki, I had never heard of this until you posted about it, but if you do a Google image search for "concrete bag retaining wall" most of them look pretty rough, and even the better ones don't look very residential.
  • Doug is correct. It would not be a recommended product for a front yard curb appeal. .
  • KMS Woodworks KMS Woodworks on Apr 01, 2012
    I've seen some walls built with used "chunks" of concrete ( sidewalk pieces) To me they would be leaps and bounds better looking than the bag route. and might be found for free in you local community. Concrete runs about 4 bucks a bag and at height of 3" or so would require a good number to provide 3 feet of wall. from a cost perspective basic wall blocks would look much better and be could set them up as a pair if you need to extend beyond the 2 foot height limit.
  • Vicki T Vicki T on Apr 01, 2012
    Thanks Douglas, John and KMS. KMS, I like the garden block but how will it hold up to putting earth behind it to level out my lawn? Would the weight of the soil push the blocks out onto my sidewalk? As for the look of the concrete bag wall....bleh. After Googling it I can't say I like the look at all.
  • Be careful with all the water, if you add as much water as what you are talking about the concrete will have no strength or it will just deteriorate. Your better off to build a form and just pour the concrete in it.
  • Michelle E Michelle E on Apr 01, 2012
    I have used those blacks for making raised beds....they hold up ok IF you make sure your first run is perfectly level. Any slope and yes, they will bow out. Personally, if I were a supporting wall that someone may walk on, I would use rebar to help provide support or put a few rows in then back up a bit and start another run for stepped effect making them at least 3 deep you could plant ground cover or flowers in the filled areas. A less expensive option if your going in straight lines and they are readily available for little money- would be railroad ties. 10 yrs ago, I could find those easily for free or cheap- I used them as borders around fence, but they could be stacked and used for a retaining wall.
  • Southern Trillium LLC Southern Trillium LLC on Apr 01, 2012
    A couple thoughts. If the water is running off your yard, you first need to address why so much is running off. One possibility is that you may be overwatering it. This means that at the point the soil cannot absorb the water any faster, the irrigation is still running and the rest begins running off. There are 2 easy ways to fix this. One is to stop watering at the point of runoff, then wait a while and water again if it is needed. The other option is to change the type of sprinkler to one that outputs at a slower rate. At a slower rate, the soil can take in the water before it runs off. Now for the wall, the choice of materials will depend on how high the wall is going to be, and it also is important to know what is the angle of the soil going to be behind the wall after construction of the wall. For a low wall, you can use the small concrete blocks that KMS linked to. 2 feet is the max height for those blocks, and if built on a proper base and with the first course level, you can backfill the wall up to 2 feet tall. There are other important steps in this process, such as proper backfill and drainage to remove water from behind the wall. A treated timber wall should also not go much higher than ~16" before adding deadmen, which anchor the wall into the backfill. The timbers alone do not carry enough mass to hold up against the mass and force of the soil behind the wall. This is where the deadmen come in to play. Railroad ties might be able to go up slightly higher, but I would still want to see deadmen installed once you go above 3 courses of railroad ties. Again, you are trying to use something that is only 9" deep to hold up to all the pushing of the soil behind it. Now, there are many other block choices that can be used to build a wall up to 48" without major reinforcement. The blocks are much larger, much deeper at 12", and much heavier at ~85 pounds per block. All these dimensions and mass allow the wall to be built and hold up against the pushing of the soil behind it. These walls are also not vertical, but have a batter. This means that each course is slightly further back. This angle allows it to go higher than a pure vertical wall. Just imagine if you were to stand straight up and someone pushed on you versus if you leaned forward as they pushed on you. You can resist much more pushing if you are leaning against the force. So the answer really depends on how high your wall needs to be, what your budget is, and who will be doing the work. If you are doing it yourself, the wooden walls are much more homeowner friendly. We have had several clients try at moving some of the larger blocks when we are building with them. But it is one thing to pick up and move a single 85 pound block, but when there are over a hundred of them, it changes the story. If the wall is only around 2-3 feet tall, there are many block options that can be used, and will weigh around 40 pounds at most per block. There is still a lot of work in building a segmented retaining wall properly, but it can be done by a homeowner. Just remember, on any wall, the most important step is the footing and the first course. The next most important thing is the drainage and backfill to handle water behind the wall. If you skip on either of these, the wall has a good chance of failing.
  • KMS Woodworks KMS Woodworks on Apr 02, 2012
    Of course there is always the "landscape timber" route. Last summer I built a "parking spot" for my utility trailer. With my design the "sides" act as "deadmen" and keep things secure. along the back mine is close to 5 feet high.
  • Vicki T Vicki T on Apr 02, 2012
    Thanks so much everyone! I have gotten a wealth of information and an education to boot! That is why I come here with my questions first :)
  • Ayu32034565 Ayu32034565 on Dec 06, 2017

    how to construct R.C.C retaining wall?

  • AuntQueenie AuntQueenie on May 05, 2021

    can you make berms? (basically a small hill) they can also help street noise be less intrusive as sound bounces off structures, like a house. check out this website.