Sleeper retaining wall advice ?

Scott bue · 15 May 2020 at 18:38

Hello im just looking for some advice on something. Im looking to bulid a 3 tier system for my back garden stones at bottom , decking middle and artificial grass on the top. im going to use sleepers 10x5 on their narrowest side to build retaining walls just along the fronts of each level . Im pretty happy how to fix but wondering about the whole drainage part , ive heard to put them on a base to help drainage but what would this be as its all stoney soil underneath (it’s quite a good base under the back garden ) also what menbrain to use behind the sleepers and do i need to use shingle ? How would these go sleeper - menbrain stapled in - shingle scatterd behind or sleeper - shingle - menbrain? Thanks everyone

Scott bue · 15 May 2020 at 18:52

Scott bue · 15 May 2020 at 18:54

https://ibb.co/Ct53VzD
https://ibb.co/swJP4CT
Here’s a picture of my back garden and how the sleepers will look from someone elses picture

Hedge · 15 May 2020 at 19:25

Just built one myself in our garden.

Mine is 4 sleepers high with sleepers concreted in vertically to support them. I plan to backfill mine this week. I have landscape fabric which I am gonna run down the back of them then fill most of the void with old smashed up patio slabs that I removed and then some mixed hardcore that I had from another project. Yours looks like it needs to retain considerably more as there is someones garden at the top end. Therefor you should probably give drainage more consideration than me.
https://www.pinterest.co.uk/pin/474496510737352593/

that seems to be one way to do it.

You might need to run some kinda drainage pipe to divert the water away.

Scott bue · 15 May 2020 at 20:10

Thanks for the reply that’s pretty much what im doing but what base did you use for under the bottom sleepers? So behind the sleeper how should i attach the landscape fabric and also what is the actual name of it is that for waterproofing the sleepers? How do you attach this on and is it sheet to sleeper then stones on the other side and fill or sleeper then stones on the other side sheeting then land fill? Thanks again

Hedge · 15 May 2020 at 20:26

My sleepers are on a bed of hardcore that I compacted down a bit probably only 4 inches or so. Then they are screwed into vertical supports. I don't see them sinking or anything.

Just dig a channel where sleepers will go. Fill it with gravel. Pack it down then start your bottom row. Some people put bolts or rods into them and then dig a small hole to fill with concrete then drop the bolt/rod into the concrete.

I think walls over 1m or so need building control visit. Maybe I'm wrong. Worth checking.

I'm just using landscaping fabric. Some people talk about using a damp proof membrane but I personally think that's just more likely to trap moisture against the wood and stop water draining. Especially in your instance where you would want the water to be able to weep through gaps to relieve pressure.

Hedge · 15 May 2020 at 20:29

As for where to fit. I'm personally going to run membrane down back of sleepers then up the earth behind. Then pour gravel into the valley between.

Then I'll cover top 6-12 inches or so with a soil / turf I expect.

Bear in mind I'm just a DIYer and no doubt experts will tell you different. In my case the wall is retaining 600mm and only about 4m long.

Scott bue · 16 May 2020 at 01:09

Many thanks so if i lay the sleepers onto abit of hardcore bed them in slighty in a bay put posts behind concreated into the floor then use a landscape fabric behind the sleepers .
Can you draw me a picture of where to put gravel behind the sleeper along with the sheeting If you can i can’t picture it fully that’s the only concern i have ive never done anything like this before and don’t under the hole sheeting and using shingle or gravel as you say. Would broken bricks be the same Or not do the same for the water? Also when the water runs down beneath the bottom sleepers down would the hardcore not catch the water and hold it in the bottom of the sleepers? Thanks again

Hedge · 16 May 2020 at 08:11

There are quite a few images online if you just search sleeper wall or sleeper wall back fill etc.

Get a string line and mark out your post positions at chosen distances. Dig the holes (I recommend using a post hole borer. Draper do one on amazon for about 30 quid), concrete your posts in. Dig a bit of a channel. Fill it with gravel. Level sleepers onto it and screw them to posts then build up.

Gravel just stops the sleepers sitting in wet soil for prolonged periods. The membrane is to stop soil seeping through wall.

Water will find the easiest route so just keep that in mind.

I personally put the vertical sleepers in front of my horizontal ones so they are visible

Watch this video

ergonomics · 16 May 2020 at 13:01

Hedge said:
I personally put the vertical sleepers in front of my horizontal ones so they are visible
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I've just done a wall 3 sleepers high (600mm) and this was the way to do it imo. I considered vertical sleeper posts behind the horisontal wall to look cleaner but the weight behind the wall will be pushing those horizontal sleepers away which are only secured by the timberlok screws. With time, those screws will tug out. Having the vertical posts infront of the horizontal wall means the sleepers are being pushed against the posts. Assuming you are leaving good depth of the vertical posts in the ground and using enough concrete/postcrete, they won't go anywhere and over time less likely to separate.

Hedge · 16 May 2020 at 14:27

ergonomics said:
I've just done a wall 3 sleepers high (600mm) and this was the way to do it imo. I considered vertical sleeper posts behind the horisontal wall to look cleaner but the weight behind the wall will be pushing those horizontal sleepers away which are only secured by the timberlok screws. With time, those screws will tug out. Having the vertical posts infront of the horizontal wall means the sleepers are being pushed against the posts. Assuming you are leaving good depth of the vertical posts in the ground and using enough concrete/postcrete, they won't go anywhere and over time less likely to separate.

Yeah exactly my thought process when I did mine.

I used oak and they come in lengths about 2.6m. I left them almost full length and the verticals are 2.3m apart. There are no ends visible as the posts cover it. Looks nice.

jellybeard999 · 17 May 2020 at 00:31

You could drill through the sleepers, put some rebar or threaded rod through the holes and postcrete the bar/rod in. Should hold if it's deep enough.

rah^ · 17 May 2020 at 18:31

As above

Mines been in a couple of years about 8m long 600mm high and just the bottom have some 600mm bars through them to hold the wall in place