Sakrete/mortar bag retaining wall.

Granbury, TX(Zone 7b)

We moved to a house on the Brazos outside of Granbury, Texas last October. Our yard is about 400' long and about 30' behind the house it slopes down about 20' over the next 40', levels out to a gentle slope for around 150' and then falls about 15' to the river. We need to do something with the first slope to get it more manageable and are considering terracing it. We've talked to a couple or contractors who suggested that we use bags of sakrete stacked about 4' high every 12' or so. Has anyone used this method? Have you been happy with it? Any other suggestions that wouldn't put is in the poor house?


So.App.Mtns., United States(Zone 5b)

Well, bags of sakrete (or gravel mix) certainly will get hard when they get wet, but I'd stack them offset as each row goes up, and staggered across the seams in the rows. I'd also pound in some 5 foot lengths of rebar to keep them stable and from sliding down the hill.

I do think that's a very expensive way to make a retainging wall/terracing.

The problem will be covering the ugly bags once they are "cured"

Okeechobee, FL(Zone 10a)

I haven't done it, but have seen it done often around corrogated 20" drain pipes under driveways all across the south. I agree with darius on the placement and re-enfocement, but you could manipulate planting pockets when placing the bags. It really looks stragily for awhile, cause the bags have to get soaked then form-up, then the wrapers just slowly wear away over time..

Granbury, TX(Zone 7b)

Did you mean "inexpensive"? Because I'd been told that this would be the least expensive way to do it. Oh, how I'd love to use native stone!!! I know it would take time to get the sakrete looking good but I'm envisioning trailing plants, tall perrenials and shrubs to cover the walls eventually.

I think the contractor I talked to seemed competent. He said he'd use the rebar, plenty of drainage pipes and back fill with large stones for a few inches to keep water pressure from builing up. I asked if we couldn't stain it or put seashells in it or something to make it more attractive and he said that isn't the way it works. Don't know if it would work to use some sort or stucco over it once it's cured. I'd like to intersperse some troughs...been dying to try my hand at that.

So.App.Mtns., United States(Zone 5b)

sugarfoot, call HD or Lowe's and check the price of a bag (and it's ht x width x length), and figure how many bags you'd need to go up four feet. Then check the price of used railroad ties or pressure-treated 6x6's. Compare how many of each you'd need for the same sixe area. Don't bother with labor costs at this point, just materials.

The drainage pipes and stone backfill are of utmost importance no matter which way you go.

I think you could stain the mortar once the paper has deteriorated, not sure a stucco layer would bond well.

Granbury, TX(Zone 7b)

Wonder how long it would take the paper to wear away. I can see myself down there picking paper off a thousand bags of sakrete! ;-)

Okeechobee, FL(Zone 10a)

Well, now get this contractor to show you where he has done it or give you an address where you can check it out.
Then preferably photograph it for posting here.(and we will all speak-up for sure.)
It sounds like he has a plan with the foundation. Maybe he has a system of wetting and removing paper bags.
My question is about the "things" that leach out of concrete that you can't get plants to grow in.
I like the railroad ties too.

Granbury, TX(Zone 7b)

Oooh, things leaching out of the concrete worries me. Will have to try to find out about that. My "soil" is very sandy and will need much amendment to have the kind of garden I want. Do you think leaching would be a continual problem or would subside after the initial setup?

So.App.Mtns., United States(Zone 5b)

Some materials always "leach"... even glass, but most of it dissipates after a few months. The only thing that ever worries me about leaching is if I want to grow edibles.

Granbury, TX(Zone 7b)

Just had a visit from one of the contractors we had look at our slope. He estimated $23,000 just for the bags of sakrete. LOL and crying at the same time. That is way beyond my budget. I suppose that I'm going to have to figure out how to get the slope planted with groundcovers, etc so that we don't have to mow it and yet it will have erosion control. Will have to get out my old gardening books/magazines and see if I can find any ideas.

Okeechobee, FL(Zone 10a)

Are you and DH retired? And still limber? I think you could rent a mini-backhoe, and do the RR ties.
It helps if 2 or 3 different people need equipment size chores done. We rent for the cheapest price and do 3 yards, sometimes working into night to save on rent. A lot could be done fo 23 grand in my book.

Granbury, TX(Zone 7b)

DH and I are retired. I'm in pretty good shape but don't know if I can lift much more that 50 or 60 lbs right now. DH fell off a 3 story building in 1985 and he can't do as much as he would like. The problem is that the 23K was just for the materials - no labor. We're thinking that we'll have to settle for a path that takes some of the steepness out and just shoring up the areas that are cut into the hill instead of terracing the whole thing. I know I could eventually get the hill planted so that we don't have to mow it anymore and it could be quite beautiful. I've got to kill the bermuda grass and enrich the soil before I can get started. I've been wondering if I could take some of our moving boxes and nail them into the slope with a few layers of newspaper under them to kill the grass. Then when the grass is dead turn it all under with some good compost mixed in and then plant. If I did about a 15 X15 or 20 x 20 area at a time, I could plant the first area pretty thickly while the second area was dying off. The move some of the plants from the first area into the second and keep going like that. Then I wouldn't have more than I could handle at any one time and would also have a chance to see what is going to do best here. I'm really itching to get started.

Okeechobee, FL(Zone 10a)

That itch is a good one. I think you have a good plan.
You could get some # 9 wire and fashion some big staples to hold them down. It's about twice as big as a coathanger wire and you really want them to stay covered. You might be more knowledgeable about nails than I am. My staples would be 4 - 5 inches wide an have 8 inch tines.

Coopersburg, PA(Zone 6b)

linda - your yard kind of sounds like ours - from the road, we slope down to a creek. what we've done in some places is create our own terraces with lasagna gardens and we've also used free wood chips from either the electric company or tree trimmer companies. a couple free truck loads of chips sure goes a long way in building up a sloped area.

Olympia, WA

I wouldn't worry about concrete leaching as much as I would the leaching from railroad ties and/or treated lumber.......concrete bags here would be less than $2 each.

Well, just my $2.00's worth......


Gordonville, TX(Zone 7b)

Bumping this for an update on your project sugarfoot.


Oakland, CA(Zone 9b)

I believe concrete leaches lime but not much else. So in your alkaline soil you'd add some sulphur and get your soil tested for a recommendation of the correct amounts.

Talk to an engineer to get an idea of how the job should be done PROPERLY. That way, when you choose from your alternatives, you'll have a much better idea of evaluating not only costs, but the vendors' respective competence.

We have a double slope on our property, front to back and side to side. For our many retaining walls we used concrete block. I felt as you do, by using appropriate plants, most of the face would be hidden anyway,. Only in one area (garage driveway retaining wall) did we need to use the really heavy 36-lb blocks since it's 6' tall at the highest point. All the others are the smaller 15-lb blocks from HD or Lowe's. Our soil is heavy clay although the first 6-8 inches were moved and replaced with lighter weight compost. In three years we have had no settlement problems.

No matter what material you use, the base excavation and drainage/support behind the wall is absolutely critical. Skimping on this guarantees a bad wall with higher risk of failure. Water adds enormously to the weight of soil and redoing walls isn't a fun or cheap job.

One reason we like the blocks is that you don't need deadman supports, just a good base of the proper depth and gravel drainage behind.

Here's a link to our Yahoo photo album which has a few pix of small-block retaining walls. This link is suitable for dial-up net access users.

If you have broadband, you can see a far more comprehensive photo collection on our website which is on Comcast. I don't recommend this for dial-up users as it's extremely photo-heavy. However, it shows the garden installation in phases. The concrete block was used in the Front Yard, the North garden bed (just a few), the Back Yard, and the Barbaricum (most recent install).

Marysville, WA(Zone 7a)

We also use the retaining wall blocks (gardenblocks) for all of the raised beds as they seemed to be the least expensive ($1.25- $1.75 ea.),are light enough for me to carry (about 25#),and can be easily removed if a design "needs" to be revised.The various sizes will accomodate walls from merely decorative to structural.Once the drainage and subgrade are in progress can go as fast or slow as you want,a factor for us due to weather,finances and unforseen interruptions.

Thumbnail by balvenie
Okeechobee, FL(Zone 10a)

Wish I could afford to do that. Looks terrific.

College Station, TX(Zone 8b)

Bioengineering is the way to go. Vetiveria zizanioides nash would be the ideal, although it is generally rated to zone 8a, one above yours. Still as an experiment this would be a lot cheaper in the long run. Do a google on vetiver grass erosion to see what I am talking about. It may be better than concrete, It puts a mass of roots down to the core of the earth (minus a few feet to compensate for poetic license) And collects dirt at the surface. It also is a great companion plant for many crops including fruit trees. Additionally the root is the base for fabulous stick insense and is distilled to make the vetiver scent. The leaves are used for basket weaving. Just talking about it makes me want to buy some and I already have it! (Not enough yet) This site, has one rated for 7b. They are in Raleigh, NC, so they may have selected for something a bit more hardy. On their site however is this qoute: -Tony " I consider every plant hardy until I have killed it least three times." Avent, so they may be liberal with their ratings. Garden watchdog has them at 86%.
There is another wonderfull option, sunchoke! I'm told that if you kill it, move, you soil is poisonous. It has often been used for erosion control, makes a lovely flower, and is quite tasty. You will have to mow where you don't want it to progress, but if society collapses you will thank me for the suggestion. (Not for the collapse mind you, but for all the food you have buried underground :) Ok I just looked it up and I can't find any references to sunchoke being used for erosion control. Shading out other plants and weeds, yes, erosion control, no. You could also plant a bunch of willow. In the spring you cut a section of wood and stick it in the ground depending on the environent you have about a 50% chance it will become a tree.

This message was edited Mar 7, 2005 1:59 PM

Hillsboro, OH(Zone 6a)

I hate to say foot for foot or inch for inch, railroad ties are not cheap. They are not cheap here anyway. Up here, the best quality relay is $16 then there are two levels below that. They are supposed to be 9" x 7" and not a single one out of 10 were! LOL They were also supposed to be 8' long and varied as much as 5" in length from one to the next.

Then you have another issue, if you are considering doing it yourself. I am strong and haven't found much I can't do and I don't give up easy. The railroad ties kicked my butt! I finally bought a heavy duty steel wagon. It took both hubby and I to load them one at a time. He pulled and I pushed to get each to the back yard. On the scale you want this wall built, I wouldn't do it yourself unless you have a lot of really good friends. :)

I have not seen mention of it in awhile, but a few years ago when I was looking at erosion control, I found several reports about using certain ornamental corn I believe. I want to say it was broom corn but I won't swear to anything. It might have been a grass. The stalks are buried upright and left in the ground. I have also read about and seen kudzu (not the plant, just the dead vines) weaved in and out around poles for the same thing.

Kingston, OK(Zone 7a)

The best way to go is go out and buy a cheap cement mixer. Lay down forms for the walls and reinforce with rebar. Pour and back fill with gravel and a dranage pipe.
Concrete is a lot cheaper then pre mixed when you do it yourself.
Get a load of sand and gravel hauled in. Buy a good wheel barrow.
You can finish the front just like you make hypertuffa any way you want.
Do one terrace at a time.
It will last a lilfetime. Regards Ted

Fort Worth, TX(Zone 8b)

I am about to do the Sakrete thing. I live just north of Sugarfoot. Mine will only be three to four bags high and about 200' long. The railroad ties will be out for me due to the chemicals. Check out . Colonial Country Club in Fort Worth has used it on their 10th and 18th holes. One of the parks in Fort Worth has also done it. Looks pretty sharp. I have done around 40 bags. I tore one open. I was wondering if you need to poke holes in the bags to help the water get in. I am off setting like a brick wall. Every fourth bag, I will put 18" rebar into the ground with every 8-10 feet putting a horizontal brace (U-fence post) 3' - 4' into the ground.

Cicero, NY(Zone 5a)

Is that picture showing the bags of concrete?
If so I may try that on my shore line

Fort Worth, TX(Zone 8b)

Yes. Sometimes you have to get pretty close to it to see that it is just bags of cement. I think it is really good near water. You just lay it out and it hardens after it gets wet. I have put out about 50 bags so far. I have them three high. The paper hasn't started coming off yet. Since you don't have to mix it and you really don't have to do much to level it, a crew can do it pretty fast.

N. Mississippi, MS(Zone 8a)

sugarfoot - keep in mind that the paper has a plastic lining under it at the top and bottom of the bags. I have seen someone use this method before and boy did they end up with a mess. Darius is right on the money suggesting rail road ties supported with large diameter rebar. You can usually get good ties from a resale yard for about 5 to 10 bucks per tie. I think in the long run that would be less money than a bunch of $3 bags of concrete.

Fort Worth, TX(Zone 8b)

Sugarfoot, for the sake of the people at Pecan Plantation and Lake Whitney, I suggest not using the railroad ties. In many places you can't buy them because of the chemicals used. You live too close to the water supply for those chemicals. I live a couple of hundred yards away from one of the Benbrook Lake creeks and many houses in my neighborhood have wells. The wall I am building has runoff water that goes directly into the creek. I suggest either the bags, mixing a cement wall or start finding native rock.

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