# Suggestions for a cheap - reliable retaining wall

Discussion in 'Homeowner Assistance Forum' started by thatgamesguy, Apr 25, 2014.

1. ### thatgamesguyLawnSite MemberMessages: 1

I've got a backyard project that needs to be done as cost effective as possible. Its a double retaining wall. The problem is there is a third block wall on top of the two retaining walls, so it has to support some weight.

Attached a diagram, kinda sloppy, I apologize. I'm leaning towards two short cantilever walls, however I heard there are lots of calculations involved. How do you figure out the width and slope? footing?

Better ideas?

2. ### AGLALawnSite Bronze Memberfrom Cape CodMessages: 1,778

" I heard there are lots of calculations involved. How do you figure out the width and slope? footing?"

Any wall higher than four feet requires a structural engineer to do those calculations and stamp the plan or details. Any combination of walls (terracing) are considered one structure unless the horizontal distance between the BACK of the lower wall and FRONT of the next wall is at least 1,5 times the height of the lower wall.

You absolutely need a structural engineer both by law, and to cover your butt, and because failure of a wall like this can kill people.

A cantilever wall is probably not the most practical because it requires excavation for a wide footing that could cause that existing wall to fail during construction.

Your cheapest and safest option in my opinion would be a single modular block wall 6' high and allow a 6" sloe between that and the existing wall. You'll still need it to be engineered, but that is not as scary as it sounds.

Don't put yourself in the position of taking on huge liability because your customer is too cheap to take it on himself. That would be like running out into the interstate to get a hundred dollar bill for someone who won't go after it themselves so that they'll give you a dollar.

If they won't do it right, run away. Don't own their problem.

3. ### lumberjack1986LawnSite Senior Memberfrom Columbus, MSMessages: 287

Does the existing wall happen to extend down 13' and you're backfilling against its face?

The engineering isn't terribly expensive, but the project itself will cost to do it properly.
Posted via Mobile Device

4. ### SkeetShooterLawnSite Memberfrom Seymour, CTMessages: 54

I would listen to AGLA... Get a good engineer for this. Trust me... I should post you a picture of my retaining wall at my investment property which was not done correctly... (Prior to me purchasing the house)

A good engineer will tell you exactly what options you have and should also be able to help you with referrals to good contractors.

5. ### agrostisLawnSite Silver Memberfrom Winston-Salem NCMessages: 2,545

You can be cost effective by shopping around, but it's not going to be cheap. If you think that it's less expensive to do it halfway, wait until you see the bill for cleaning that up and then doing it right. Ask this question in the hardscaping section for a more exact answer. Good luck.

6. ### danieljoohn18LawnSite Memberfrom Pittsburgh, PAMessages: 24

Cheap and reliable don't go together in the landscaping world.