My daughter's garden slopes down to the main road and she's like to get it dug out to create off-street parking. It'll need a retaining wall to hold back the soil obviously. It's not steep but we could be looking at a 3-4ft high wall.
From the affordability point of view I've been wondering about the use of gabions, maybe fill with decorative rock rather than a conventional blocks and mortar wall.
Any ideas how this would compare price wise?
Tim
Would you not have to make the wall curved so the pressure from the soil on one side makes the wall stronger instead of knocking it over at the next monsoon we seem to get in this country? I've seen the result of not doing this at the bottom of the hill I live on! Brian
As others may have suggested, put a back slope on it (into the hill) and that will help considerably. I've seen such walls 8-10 ft high made of heavy density concrete blocks with a slight angle, so 3-4ft is not going to be too hard.
If you used concrete blocks, vertical would be possible with good foundations. A curved wall adds strength.
Not certain of the best slope angle - but the ones I've seen have been
10-20 degrees off vertical. With a big enough angle, you could get away with dry walling.On the theme of angled and drywall, there are these:
They have a tab on the back to they interlock, but are otherwise laid dry (except the top course has something to help stick them).
Those do have some explicit data sheets on max heights they will retain, and how to manage extra height.
A variation would be to do 2 x 2' walls, one set back from the other and fill the middle strip with plants.
Don't forget drainage holes in the bottom[1] and ideally a backfill of free draining aggregate - that will alleviate water pressure when it rains a lot.
[1] The Marshall ones drain through the dry joints.
Gabions are much cheaper, but eventually rust through & collapse.
NT
I have seen gabion walls several metres high used as retaining walls. As far as rusting away, they used gabions on the M62 in the Pennines and they are still there since the early seventies. The beauty of them is that they allow excellent drainage.
Richard
In message , Tricky Dicky writes
Elsewhere you see concrete *shelving* which allows soil to penetrate and slope at the angle of slump. This allows free drainage and an opportunity for grass and flowers to grow.
I doubt you could purchase these for home use but something might be achieved with sets of concrete barge boards.
If it is on to a main road you need to check the planning permission side of things, in particular the requirement for visibility splays.
To retain soil at a very shallow slope they work better. In such situations, plant roots can be used to bind it together for the long term. And even when the gabions rust the stones stay put. A retaining wall is a different matter.
There are always SS gabions, they don't normally rust.
NT
You need planning permission for vehicle access on/off the road, and if there's a kerb and/or pavement there, a council approved contractor will need to make it suitable for vehicle crossing (dropped kerb, replacing paving stones with weight-baring surface, etc). They'll also consider things like proximity to junctions, loss of on-street parking bay (particularly if revenue generating), drainage of the car standing area, etc.
In message , Andrew Gabriel writes
They don't like loose shingle which could migrate to the highway either.
>
What about the cost of the stones, though?
Have something to add? Share your thoughts — no account required.
Ask the community — no account required