View Full Version : Need help with Retaining Wall

03-07-2004, 09:31 PM
Ok, got a guy that wants a 125 linear foot wall. It will stand about 4 ft above ground. The wall will protect from erosion from when thier creek collects water (aka when it rains).

The people behind them built one with bags of concrete and their's is about 150 ft long and about 10 ft tall.


1) The neighbors wall looks like the bags are just stacked on one another, will that work? NO binding/ supporting things or whatever?

2) How do I build a good foundation? I know I will have to excavate to level it all up and backfill some stuff to get it back how they wanted. But the creek is always bone-dry until it rains, and then it fills up. So how do i go about making a solid foundation?

3) The customer said his neighbors hired a construction company to do theirs and they had to lift in a bobcat with a crane and drop it down in the creek bed.


03-07-2004, 11:30 PM
I do creek bed installs and walls within and think you will need to decide before you begin who will be paying the engineer who will design and spec your wall. Also you have to factor in your local DNR since your in a water shed and they might or might not have a say in how they want the wall built. All walls hate water and having lived in Texas can only imagion what the creek looks like when it becomes a gully washer

03-08-2004, 03:36 AM
Looks like its alot more complicate than I originally thought. May I ask what a DNR is? An any inside information on the foundation / stacking? Thanks.

03-08-2004, 07:54 AM
DNR is department of natural resources each state might call it somthing slightly different. The base and the stacking is going to be determined on the engineering specs associated with the class of block you uses. IE due to running water across its face the type of block you use will be more costly than if you were building your typical wall.

03-08-2004, 02:52 PM
Well I will check with the city and see what they require. But I know the wall behind this customers house had to have a permit, and I will be doing the exact same thing as this other company. So I'm sure it will work out. But can you still answer my question about foundation. Do I need to pour a foundation, excavate and fill in with sand? And of course the wall will not be straight up, front the bottom it will tilt further back about 5-10 degrees. It will only be 4 feet high. So under 8 blocks high.

03-08-2004, 07:42 PM
We have never done one with a poured foundation. We use limestone with fines. However in Texas you might want to find out if their is bed rock right below grade..................if so that will solve some of your issues. If we put a retaining wall into a creek bed area we usually front the area with large limestone rock to keep the water from washing at the sub base

03-09-2004, 04:24 PM
Ok, thanks. Anyone else got any tips? I was looking at renting a Bobcat Compact Excavator. To level and shape this crap out. I've got little space to work with. Is there a skid steer that has a boom/arm on it right a bucket like a little Bobcat would, or am I gonna have to move up to a tractor sized item?
I know I'm gonna have to use a few thousand 80lb bags of concrete for this thing.


Capital what would you charge for a typical 125ft x 4ft wall with these concrete bags with leveling (it's fairly leveled right now).

I can price the cleanup of brush and backfilling, but never done a wall like this before. I've done stuff like this at my house, but nothing that would be this big. 4 ft tall doesnt sound hard though, couldnt be too much trouble.

D Felix
03-09-2004, 05:39 PM
Check out http://www.redi-rock.com. I think those blocks would look much better than "bags of concrete" that have been stacked. If you can get a skidsteer there, I would suggest a Bobcat T300, it should be more than capable of slinging around the Redi-block. They are big blocks, and wiegh a lot. The base blocks wiegh ~2500 lbs each, the middles are ~2200, and the tops are ~1500, that's for the straight blocks, not the planters.

I haven't used them before, just looked into them.

You can use a Bobcat excavator to dig the base, or a backhoe attachment on the skidsteer. I would use a flowable fill concrete base for these blocks, I can only imagine the frustration of messing up the base when one of these blocks slides. See the thread titled "Am I nuts" for an explanation on flowable fill...


P.S.- Ever been to Philmont?

03-09-2004, 07:05 PM
Um, the wall isnt visible from the property, and concrete bag look looks just fine. It's what he wants, plus its the least expensive thing. I know I have to rent a crane for that day to get the excavator down in the creek, unless I get drop it down with my truck, and then tow it out. I'll get pics this weekend and show you all what I'm talking about. Thanks.

03-09-2004, 07:07 PM
Dan? I'm not dan, but i've been to philmont twice, and going a 3rd time this summer.

D Felix
03-09-2004, 10:24 PM
Dan is my name, sorry about the confusion...

I too have been to Philmont twice, hope to go again someday if my knees will take it.

Back to the subject at hand though, how are you planning on tieing the bags together to form a solid wall?

I guess I'm a little confused as to how bags of concrete (we're talking sacrete, right?) will hold up against a flowing creek...

You're gonna have to have a pretty d*mn big crane to lift in any kind of decent sized excavator.... I think a 331 wieghs between 6-7k, and that's a fair amount of wieght for a crane depending on how much reach is needed. If you have an access point down to the creek, you should be able to drive the excavator right down to it. Use the boom and bucket to guide you down and back up the hill. Pucker factor may be high, but you should be able to do it if you've used one enough.


lawn jockey
03-09-2004, 11:25 PM
If Im understanding him right,He is going to use this wall so it does not erode the creek banks during high water periods. We have the same walls around here for the same purpose, but what Im not understanding is why you would need to lower the excavator in the hole and yes a 331 weighs close to 7500#s. Why would'nt you just dig the creek bank back enough to cat the excavator down like DFELIX mentioned?

little green guy
03-10-2004, 01:52 AM
I'm still lost on the whole "bags of concrete" i've never seen or heard of anything like that. As far as getting the excavator into creek I would think you could just dig yourself a ramp right on down. A crane sounds like more of a pain on the neck and it's gonna run you at least 1000 bucks for a day. Also you may want to check with the EPA to make sure you'r not going to run into problems there too.

03-10-2004, 01:54 AM
I know at first blush this job probably looks relatively simple to do.
Don't let it fool you, this sounds like one of those times you should sub it out. Take 5% for your trouble and hang out during the construction and learn what you can.
Take those photos you were talking about with special interest on the creek area as far up stream and down stream as you can see from the base area of the proposed site. Also at the base of the wall site.
Don't ever be shy about turning a job over to a qualified sub.
It will save your reputation.

03-10-2004, 11:16 AM
Yeah, I'm gonna go check out the site this weekend when I'm home on Spring Break from school. I think I should be able to drive it down in from a little further down the creek. I can pay my dad to excavate if I cant get the handle of it. He used to use these things. And these bags are just "stacked" The creek only has water in it when it rains, so it's not flowing all the time.