Retaining Wall Materials List, Priced in Under a Minute
Build your materials list
Step 1 of 6Where are you building?
We hold different stock in each state, so this sets which sleepers and posts you can have and what delivery looks like.
How big is the wall?
Measure the face of the wall. If it turns a corner or steps down a slope, add a section for each run and tell us how they meet.
Choose your sleepers
Your steel posts
Worked out from your sleepers and wall height. Change it if your engineer said otherwise.
Your materials list
| Item | Qty | Price |
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Send this list to us
Your list is attached to the enquiry, so we can price it and check it against your site before you order.
Tell us how long and how high your wall is and you get the whole list back: how many sleepers, how many posts, what size steel, how deep the footings go, and what the lot costs. Every price comes off stock sitting in our yards right now, ready to pick up in Melbourne, Sydney, Brisbane, Adelaide or Canberra, or we deliver.
What goes into a concrete sleeper retaining wall
Four things, and only two of them come from us.
- Concrete sleepers. Steel reinforced panels, 200mm high, 75mm to 150mm thick. The thickness is what decides how tall you can build. We supply these.
- Galvanised steel posts. H beams between the bays, C channels at the two ends, all hot dip galvanised because they spend their life buried. We supply these too.
- Concrete for the footings. Buy it locally by the bag or have it trucked in. Cheaper than freighting it from us.
- Drainage. Ag pipe and clean aggregate behind the wall face. Skip this and water pressure will push your wall over, no matter how good the steel is.
How many concrete sleepers do you need?
Bays across, courses up, multiply the two.
A course is one row of sleepers, 200mm high, so a 1 metre wall is 5 courses. A bay is the span between two posts, which is whatever sleeper length you are using. A 10 metre wall at 1 metre high on 2 metre sleepers is 5 bays by 5 courses, so 25 sleepers and 6 posts.
Order the whole wall at once. Concrete shade moves slightly between pours, so if you come back for another twenty in six weeks there is a fair chance the top courses will not match the bottom ones. It is the single most common regret we hear.
What size steel posts do you need?
Your sleeper thickness picks the post for you. The sleeper has to slot into the flange, so the two are matched and there is no choice to make:
- 75mm and 80mm sleepers take 100 Standard series posts. Garden walls, retaining beds, levelling a backyard.
- 100mm to 150mm sleepers take 150 Heavy Duty series posts, certified to 4.5 metres with engineer approval. This is what most structural jobs land on.
- Anything over 2 metres moves to the Super Heavy Duty range, 200 to 310 UC, cut to your engineer’s schedule and galvanised to order.
Two things people forget and then wait a week for. End posts are C channel, not H beam, because the sleeper only comes in from one side at the end of a run, and every wall has two of them. Corner posts at 90 and 45 degrees are different again. Count your corners before you order, not after the footings are poured.
How deep do retaining wall posts go?
As deep as the wall is tall. Order a post twice your wall height and you will not be short.
A 1.2 metre wall takes a 2.4 metre post: 1.2 metres standing up, 1.2 metres in the ground. Footings run about 300mm across for garden walls and 450mm once you are at a metre or more.
That is the rule of thumb, and it is a good one on ordinary ground. Reactive clay, a slope, or a driveway or shed sitting behind the wall all change the numbers, and an engineer’s spec beats any rule of thumb every time.
How far apart do retaining wall posts go?
Your sleeper length sets your post spacing, because the sleepers span from post to post. Two metre sleepers put your posts at roughly two metre centres.
Longer sleepers mean fewer posts and fewer holes to dig, which is the part of the job everyone underestimates. The trade off is weight: a 2.4 metre 100mm sleeper is a genuine two person lift, and it is worth borrowing a sleeper grab if you are doing more than a few courses.
We stock 1500mm, 1800mm, 2000mm and 2400mm depending on the state. Your wall will not divide evenly into those lengths and that is normal. Cut the last bay short, and remember the post count is always bays plus one.
What we supply, and what you will need to sort out
The list gives you quantities for everything, including the parts we do not sell, so nothing gets missed on the day.
- From us: concrete sleepers, galvanised steel posts, end and corner posts, fence brackets, ag pipe, and a sleeper grab if you need one
- From elsewhere: footing concrete, drainage aggregate, excavation and spoil removal
Common questions
Do I need council approval for a retaining wall?
Under a metre, with nothing built or driven on the ground behind it, most Australian councils will not ask for anything. At a metre and over you generally need an engineer’s design and council sign off. Boundaries and easements are treated differently again. Ring your council before you order, not after.
Do the sleepers come with engineering certificates?
Yes, and your engineer will ask for them. Our sleepers are certified at 40, 50 or 60MPa depending on the range and made to AS3600. Send us the job and we will send the certificates with the quote.
Can I pick the materials up myself?
Yes, and most trade customers do. Pickup is Dandenong South and Officer in Melbourne, Wetherill Park in Sydney, Acacia Ridge in Brisbane, and Lonsdale in Adelaide. Bring something rated for the load, because sleepers are heavier than they look. If that sounds like hard work, we deliver, and stocked lines usually move in 72 hours.
How accurate are these quantities?
Exact, for a straight wall on level ground. Walls that step down a slope, turn corners, or change height along the run need to be split into sections and worked out one at a time. Send the list through and we will check it against your site before you spend anything.
Send us your list and we will check it
Build the list above, hit send, and it lands with our team with the sizes, quantities and post sizes already filled in. You get back a firm price, stock availability for your state, and a delivery cost to your postcode, usually the same day.
In a hurry, or the wall is doing something unusual? Call us on 0485 856 986 and we will work it out with you.