# Forum Home Renovation Retaining Walls  Retaining Wall replacement options?

## finger

We have a huge retaining wall at the back of our yard. The base of the house behind us is level with halfway up our second story house. 
Anyway when we moved in it was a jungle. I finally built up the courage (motivation) to clear it all out this weekend. Upon clearing the forest I have found the retaining wall in tatters. Our local termite colonies have decimated the lot. Some of the sleepers just crumbled away. Others are still holding strong but I can guarantee they would be ravaged on the other side. 
What are my options? Can I expect the next time we get a massive deluge I find the neighbours property land sliding into mine? Or are the sleepers mainly there for cosmetics? I can see concrete behind some of the sleepers. 
How much can I expect to pay to get the pro's to replace the wall? 
Cheers 
Attached are some before and after pics.

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## Batpig

Dear Finger, 
Yes - timber Sleeper Walls are a headache-in-the-making-down-the-track at the best of times, and can be an absolute nightmare if installed in a backyard where access to machinery dissappears when the house is built... :Frown:  The timber just never seems to last like the guarantee says it will  :No: . By the time they let go (usually about 7 years down the track - ie. around about the same stage as most marriages...), the manufacturer's stampings have all long since dissappeared, so it usually falls back on the Builder (because a lot of them go into Speccy homes). But I'm not sure what the extent of the Builder's liability is in such a situation  :Confused: . I take it that you're in an established suburb, however...   

> Can I expect the next time we get a massive deluge I find the neighbours property land sliding into mine?

  Whilst Retaining Walls that are under-designed but properly-built (if that makes sense...) generally don't fail in a sudden burst, it is indeed possible for something like a Boulder Wall (which I'm hoping are now illegal due to the stupidity of the concept...), or a rotten/termite-chewed Sleeper Wall, to come down with a sudden crunch during wet weather. Since you're on the low side, and the wall in question is on your side of the fence, it is most likely that it is retaining a "Cut" embankment - as opposed to holding back the neighbour's "Fill" - and as such there shouldn't be too much movement of soil involved if the thing comes down during moderate wet weather. There's no exact answers, though, and even a small collapse is still quite traumatic to clean up and repair (and it certainly wont do the Fence anygood if the wall collapses...), so how long is a piece of string?   

> Or are the sleepers mainly there for cosmetics? I can see concrete behind some of the sleepers.

  It's impossible to say without having a really good poke around, but it is nonetheless highly unlikely that someone has gone and covered-up an existing soundly-constructed Retaining Wall with another Sleeper unit, just for the sake of improving the appearance.
It is instead more likely that the concrete you are seeing might actually be a "Fines-Free" mix that has been used for drainage-purposes in place of Gravel as a backfill behind the wall during its construction. If the concrete you are seeing is only up high, I guess it's also possible that it could be the visible traces of a Retaining Wall that was built on the neighbouring block of land to hold back some Fill (but then, if their house is nowhere near the boundary, why would they bother?)
Like I said - impossible to say. Better put on your "Sherlock-Holmes" hat and start poking around up there with your Pipe (load some Borkum-Riff "Cherry" into it first... :Rolleyes: )   

> What are my options?

  In short, for something that will last, your three options are effectively:
1) A "Reinforced Concrete Sleeper" wall of some sort. They don't grow on trees, but they are around; "Concrib" for example, is a company that does them: Concrib :: Retaining Walls, Noise Barriers, Slope Stabilisation&Erosion Control Systems
2) A "Concrete Crib" wall. Concrib also do these, if you're trying to wrap your mind's eye around the concept.
3) A "Reinforced Concrete Block" wall. Quite common... 
Some pros and cons:
A Block Wall will require the most in the way of machinery and excavation, as well as a substantial concrete footing that will make it almost impossible to grow grass within about 1m or more of that wall. Not very pretty, either. They come into their own when they are either part of a building, or are being built where there is going to be some concrete paving at their base anyway...
A Concrete Sleeper Wall will be much prettier (you can get them with an exposed-aggregate finish), but there will still be some excavation of pier-type footings involved. They could do this with a 2-Man Petrol Auger if access was a problem for machinery.
A Crib Wall doesn't require much in the way of footings, but they are an acquired taste visually. Not too bad if you grow some type of decorative climber over them, though.   

> How much can I expect to pay to get the pro's to replace the wall?

  Can't really help you there, I'm afraid. There _may_ have been one or two Threads in the past that discuss costs, but if they weren't talking about good-ol' out-of-control SEQ Tradies, then they might not be too applicable, hey?... :Frown:  
Your best next step is to see if you can sniff out some local companies that are knocking-up the components for Concrete-Sleeper walls and Crib walls. Look in the Yellow Pages under "Retaining Walls", and bring-up the websites for the mobs that give a web-address in their listing. If you see a design style that you like, ring the company(s) in question and ask them for a list of Contractors who are familiar with the system on your side of town. The companies themselves may also be able to give you a very rough idea of cost. 
Hope this gives you something to get going with... :Redface:  
Good Luck,
Batpig.

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## cherub65

Nice post Batpig :2thumbsup:  
If you have the space one option would be to build in front of the existing, Then remove while constructing new wall.
Retaining walls are one of the most expensive projects when it comes to landscaping.
You need to weigh up cost vs longevity, How long do intend living on property? Is it a quick fix?
What would be the max height of walls?

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## finger

Thanks Batpig for a very informative post. I guess it's time to start calling around. 
Edit: really unsure how long we'll be here for. At minimum, 5yrs. The wall is about 1.7m high. 10m+ long. 
We had some major rain about 6mths ago and it didn't fall over so thats a plus.

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## cherub65

1700 mm is a serious height for a retaining wall, i would suggest masonry for this height or you would need deadman style wall were anchor logs are laid into bank and two separate lifts.

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