Stone (or Concrete Block) Retaining Walls - Any tips would be great.

[razorcat]

I am in the process of moving a huge amount of dirt in place around the foundation of my house. I have had a spontaneous desire to put in a stone retaining wall in the front facing the street. About 12-18 inches high I think. It will meander slightly

Comments

[ayse]

I've done several loose-laid stone and concrete walls. There's some good basic information on the web with a minimal search. Anything under 20" should be fine to do yourself, though I will tell you from experience, hauling those stones or concrete blocks any kind of distance is a real workout. And your average car can't carry many of them. Retaining walls over 20" are starting to get precarious and anything over 36" will require an engineer's drawings in most US states, as well as in Canada I would expect. You want the shape to approximate a pyramid, so the wall is stable.

I like using the concrete retaining blocks to make a stepped-back wall with plants planted in it. I use rock-garden plants and they cover up the blocks, which on their own look pretty bad, especially if you have a lot of them. I also plant small bulbs in the pockets so there's a seasonal change in the walls. Most of my small walls like that are alongside pathways, so nothing else hides the blocks from view. My long-term goal is to change out the concrete blocks for real stones that look nice, so if that's in your budget (or if you have a ton of stones readily available from your site work) consider going that route first.

[razorcat]

If it was in my budget I would use real stone :) How do you end the wall if you're wrapping it around a corner? What do you do with the drainage?

[ayse]

I hear you on the budget. :)

When I go around the corner I like to do a rounded curve, just turning the blocks 20-30 degrees so the corner is made up of 2-3 blocks, making a curve. You could also just set one block at 45 degrees, and some block systems have corner pieces available. I use the corners as a place for planting and pull the upper layers of blocks back to make larger planting areas where I can hide the corner with a bushy perennial. Last year I took out the corner I had that was most corner-like. I just didn't like how obvious it was.

I don't have a problem with drainage; a short wall backed by well-amended soil should drain properly on its own at that depth. I'm in coastal California and my soil is pure sand, so drainage is hardly ever an issue for me. I suppose in Canada you'd have an issue with frost heaves, but I sure would not want to dig the wall foundation down below the frost line for only 12-18 inches above the surface.

[rainarana]

We were fortunate that we knew some people doing large community gardens and they dug up huge piles of stones, some that took the two of us to move. They let us have as many as we wanted so all of that was free.

[razorcat]

I don't own a vehicle so I'll be getting my blocks delivered in one shot. When I was kid my father built a rock garden out of random beautiful rocks he brought home. Someday I will own a car and do the same. You were very lucky to find free rocks. :)

[rainarana]

Oh yeah, this is Tennessee where you can't put a shovel in the ground without hitting a rock. If we'd had to go out looking for them it would have taken a bit longer, but still doable. There are some nice ones on an empty lot that turned up when they were cutting it back.