# Forum Home Renovation Retaining Walls  Sleeper retaining wall help

## the_nod

Hi all, 
I am about to build a retaining wall using sleepers and was just after some advice on a few things. I have read over this forum and found many heplful hints but just need a few more.  
My wall will be approx 18m long and 800mm high (the soil is just under 700mm high). I'm replacing an old copper log wall which was poorly constructed with no drainage (which I found out once I pulled it down). Of course I want to do it cheaply so I have been looking at all different sizes of sleepers to see which one would suit.  
At first I thought of using 200x50x2.4 sleepers for the wales and 200x75 for the posts which would be set at 1.2m apart. But then I looked at using 200x75 sleepers all round.  
To make the posts even over the 18m each post would be set at around 2.25m. Would 75mm sleepers be thick enough to not warp if the posts were 2.25m apart (to save costs) or would I need to set the posts 1.1m apart? I thought of doing that with the 50mm sleepers but most specifications recommend posts at 1.2m apart (using the 2.4m sleepers). So I thought the 75mm sleepers would be better to use. 
Also we are planning on putting in an above ground pool next to the wall. Then possibly a deck above the wall. Would I need to coat the wall in some sort of protection against pool water whether it was chlorinated or salt water? 
Any advice would be appreciated.

----------


## Earlybird

If the pool is going to be close enough to the retaining wall, could you consider using the pool as the retainer.  Timing may be an issue if you can't wait for the pool to do the wall. 
I've attached the page from the pool manual to help explain. 
I can't image there being an issue with the pool water and the retaining wall, but hold out for one of the experts to advise. 
Cheers,
John

----------


## dazzler

I have had a bad run with treated pine sleepers of late with them being so full of moisture that they shrunk by at least 10% leaving unsightly gaps everywhere, a problem I never had with old railway sleepers. 
Not sure what the answer is, but beware!

----------


## the_nod

Thanks for the advice earlybird. That's not a bad idea. That thought never crossed my mind. But I still need to build something to retain the rest of the wall. At least it would only cost half as much! Timing wouldn't be as bad if I didn't rip down the old wall!  :Roll Eyes (Sarcastic):  
Where did you purchase your sleepers from Dazzler? Do you think it's the place where you purchased them from? Or just the type of wood? It probably wouldn't help with all this rain as well.

----------


## dazzler

A number of places.  One has large green and red buildings and lebotimises its staff, the other was just a small treated pine supply business. 
I think they are cutting, poisoning and delivering.

----------


## the_nod

LOL, that's the place I was thinking of making my purchase from as their prices are very good. I guess it comes down to quality and what you pay for.

----------


## dazzler

take a cordless drill and a 3/8 bit, drill into the end and see how much moisture comes out perhaps.

----------


## LJC

Nod, 
If you haven't already, have a look at the attached,  I've seen it posted a few times on this site. 
I built a similar wall 800 high using 200x75 for wales (only because the extra thickness made the wall look good) and spaced 1200 apart.  To avoid cutting and to maintain the integrity of the timber treatment - go with setting your posts at 1200: 1200 x 15 = 18m, therefore you will only need to cut two of the 2400 sleepers (alternatively you could buy the 3000 sleeper and set the post at 1500). One tip (and appologise if this is obvious) lay out the wales first to work out where you will dig the holes, this will avoid having to cut any sleepers. 
I've purchase all my materials from the big green warehouse and have had no problems with warping or shrinkage.  What I did do however, is painted all the timber with cabot's decking oil, mainly becasue I did not want the wood to gray - this may help with the pool issue?       
good luck

----------


## the_nod

Thanks for the info LJC. 
I have seen this chart actually. I was just seeing if I would be able to get away with a larger post spacing using the 75mm sleepers. I guess I'm just trying to cut costs. Less posts means less concrete = less money.  :Biggrin:  It gets confusing doing all this research as I have seen some wall examples using 75mm and spaced 2.4m apart. 
I wanted the 2.25m spacing to make the wall look even. I didn't really want one section looking bigger than the rest but I don't think that will matter too much if the pool is covering it.  
I think I will just go with the recommendations and spend the extra money for peace of mind.  
Should I use a thicker sleeper for the posts like 100mm or will 75mm do? Also should I stick with 75mm wales instead of 50mm? 
Also how much concrete did you use LJC? This is another thing I'm trying to get my head around. Hard to calculate volume once you stick the posts in. Oh and how much decking oil did you need? 
Thanks again for the advice! It all helps!

----------


## Earlybird

> A number of places.  One has large green and red buildings and *lebotimises* its staff, the other was just a small treated pine supply business.

  Does this mean if I get a job there they'll make me Lebanese instead of Australian?  :Biggrin:

----------


## LJC

Hey, 
To answer your questions: 
1. I put 2 sometimes 3 bags of quickset down each hole, holes depth about 700/800. Didn't fill to the top.
2. Can't remember how much oil I used but a 10ltr tin is about 120 bucks
3. Not sure I really undertand what you mean about the spacing: According to the technical sheet (I'm no engineer) if you want to have the gaps around 2400 you need wales/sleepers 200x100. which will be 9 posts, 32 wales. If you use sleepers 200x50 you need 16 posts, 30 wales (check the maths).  I bet the cost of the extra thickness of the wider gaps will work out about the same?  
4.  Actually building a wall this weekend if you want to have a look at some pictures next week.

----------


## the_nod

Thanks for your answers LJC. 
Sorry to confuse you with the post spacing. I've just seen other examples where the post spacing was 2.4m using 75mm sleepers hence why I thought of asking for advice on doing post spacing at 2.25m. Check this example out:  http://www.centenarylandscaping.com....ing_Wall09.PDF 
This website also has some good DIY video clips on how to build this wall! 
Anyway I will just stick with the specifications on that data sheet just to be sure. 
I would love to see some pictures of your wall. I have no intention on starting just yet as we expect more rain for the weekend! Still need to dig the holes.

----------


## the_nod

Ok finally got my sleepers delivered. Went with the 200x75mm all round and will space them at 1.2m apart.  
I was speaking to someone about my wall and he recommended that I place the sleepers wales in a staggered pattern (like you would lay bricks)! I thought that was a good idea and would probably make the wall a lot stonger. Any views on this type of layout? 
Also I am now working out how many Galvanised bolts I will need! Does anyone recommended how I should bolt the sleepers to the posts? Should I use 2 bolts per end or 1? Should I bolt it in the middle (at the 1.2m post)? I have seen some examples of sleepers using 2 and other's using 1. If I use 2 per end then I would need around 300 bolts!!! (including the middle post otherwise it would look strange having staggered bolts with the staggered sleepers) 
How did you go with your wall LJC? I doubt you would have got anything done with all the rain we had over the weekend! I will post some pictures of my progress including the mess all this rain has caused!

----------


## LJC

Rained all weekend..dug one hole (just to get out of the house!) and it filled with water so I gave up. 
Your wales are 2.4m right? I didn't stagger my wales because I wanted to keep the integrity of the treated timber and didn't want to have to paint/treat the half pieces. 
As far as I am aware the pressure of the retaining wall does have some hold on keeping the wales in place.  And yes, Gal bolts are expensive.. the first wall I built was more of a feature wall at the front of the house.  I didn't want to have a different number of bolts per post, so I used two bolts for each post including the middle post, these were staggered on a diagonal pattern. In the opposite corner (at the back of the wall, which you can't see) I used gal screws - I had sleepers not rounds.  Rounds are a bit tricker than sleepers...What you can do is have one gal bolt at the front (say in the middle of the round and two gal screws (top and bottom) through the back of the wale or screws through the back on every second post? 
The second wall I'm building which is down the back yard, I am just using gal screws only, drilled in through the back of the wales 
I'll see if I can get some  :Photo3:  for you this weekend.  I've got competing projects this weekend as I've promised my youngest that I would build him a billy cart - maybe thats another thread?

----------


## the_nod

Didn't think you would get anything done on the weekend after all that rain! I had a terrible time with some of the dirt caving in.  
Yeah my wales are 2.4m each. I was told by the guy at bunnings that when I cut the sleepers I don't have to treat the ends because the treatment goes right through the wood. I saw this on one of those DIY videos as well. But then again I have been told by other people that you do have to treat it so once again I'm confused!  :Doh:  I will be cutting a lot of my sleepers anyway so I may as well treat it to be sure. 
I'm not using rounds for the posts. I'm using the 200x75mm sleepers.I will just use 2 bolts per post to make it look even. They are expensive but I can get them for about a dollar each (for the M10x180mm) 
Dug all the holes yesterday with a hydraulic borer. If it wasn't for the rock I would have finished by lunch but it took me all day! I kept hitting that shale type rock! Will be putting in the posts this weekend. 
Below is a picture of the wall after I removed the old logs and after I dug the holes for the post. As you can see it's a mess after all the rain!

----------


## cherub65

Treat all cuts.
See in pic old drainage pipe removed, have you made allowance for new agg line.
Install posts (don't bring concrete all the way to finished ground level) then place first row of sleepers then install your agg line with sock in a trench lower than your first sleeper. Would then from looking at photo use geo fabric over pipe as well, this will stop clay getting in pipe
This trench should have slight fall to exit point, then back fill with course recycled gravel
Leave the other end of pipe coming up to top of wall this will allow you to flush out pipe 
Good luck

----------


## the_nod

Hi Cherub65,  
I am treating all cuts with this treatment spray I got from bunnings. 
Actually that ag pipe is not from behind the old wall. In fact there was NO drainage at all which is why it started to fall over!  :Shock:  That old ag pipe was actually in front of the wall! It's a long story! Basically our lovely neighbours at the back had a leaking hot water system for at least 6-8 MONTHS! Yes I did contact council, Sydney water, etc, etc. Anyway with all that water our backyard became water logged and I dug in some ag pipe to try and drain the water away. So basically it's the neighbours fault this wall started to fall over which started a couple of years ago now.  
Yes I am going to use geo fabric and make the ag fall to the centre where I will tap into the storm water. 
Anyway I have finally got all the posts in and am ready for the next stage. I have added a couple more pics.

----------


## LJC

Your getting there Nod, 
Here is a picture of the wall I built two summers ago.  May give you an idea on how to space your bolts - rather than having two bolts side-by-side (also have screws through the back).  This is the one I used the decking oil on.  
Keep the pictures comming.

----------


## the_nod

Well I have finally finished building the wall! What a job! It all went pretty smoothly but just took a long time especially when doing it yourself. 
All that's left to do is the back fill, clean up and possibly paint the wall. Looks like I'm going to have excess dirt left over!  :Annoyed:  
How long before you painted your wall LJC? I was told to not paint it for at least 6 months to let it weather a bit.  
Here are the latest pics. Thanks for everyones help.

----------


## Lagerfan

That looks great, if ours ends up half as good I'll still be stoked. Well done.

----------


## LJC

Looks good  :2thumbsup: , just think that your next one will be quicker! 
I painted the timber before I had even put it up.  So I would say paint now.  The timber looks dry to me.

----------


## diyguy

GREAT JOB!! you should be proud. :2thumbsup: 
I am about to embark on the same kind of job ,just wondering how you get it so level from one end to the other over such a long, distance any tips?? for a novice  :Confused:

----------


## the_nod

Hi diyguy, 
Thanks for that. It's been a while now since I did that job and it's still not complete!  :Blush7:  The back fill has been done but the backyard is still a mess!  
Bascially the string line is your friend! I used a string line from one end to the other and had it very tight. Then I put in the posts with help from a friend. Once again I used a tight string line to place the sleepers. I used string line levels to get the level right. You may find that the string line will be low at one end and higher at the other depending on any slope in your land. I didn't have too much of a difference between one end and the other.  
The first layer is always difficult. Some sections I had to dig out a little and some I had to fill a little. Once you get that first row level it's all smooth sailing from then on. So bascially make sure your sting line is about the same height as your sleeper. As you lay each sleeper make sure it sits underneath the string line or dead flush with it. (you may not get it perfect). Then level up the sleeper and bolt it in. I used bits of rock, wood to prop it up or had to dig out underneath it a little to make it level. Maybe lay out all your sleepers from one end to the other to get an idea and feel on how it looks.  
Hope this helps. 
Probably the best thing to do is lay out the first row

----------


## diyguy

Thanks for all your tips when I was building my retaining wall,I have only just got around to taking a photo of it, although it was completed months ago,
just thought you would like to know.
This forum is great.
I will be building a 6x4m deck next. :Doh:  
cheers

----------

