Retaining wall not built to specifications, PC help

Sammy82 · Feb 17, 2024 9:59 pm

First time poster! We had a high retaining wall built around the property (has a slope) as part of our new build. The wall was included in the contract (HIA) by the builder and they took control of the process. The wall is made up of concrete sleepers and went through an extensive design process by the structural engineer with council sign off.

After the wall was completed and the house was being built, it became apparent there was a slight lean to one of the posts and wall sides. The structural engineer worked with the builder to remedy with some reinforced piers and then a form 13 issued.

When speaking with the engineer he mentioned that the drainage wasn’t completed as per the specifications on the plan and it could have future consequences on the integrity of the wall. For reference the geo fabric wasn’t correctly applied and gravel was put on the wrong side of the fabric.
This was only evident from photos that were taken at the start of the wall build.

We are due for PC in a week, I’m stressing a little as I want to hand over and move in, but I don’t know what our next steps should be.
Builder says all is fine, and there is currently no leaning or bulging of the wall. But what about in the future if this happens.

Should I put it on the defects list (it would be a big job to rectify and doubt they would do it proactively) or should I wait until we have another problem with the wall and then take then next legal avenues I have?

Any suggestions would be helpful. I absolutely want to move into my house (not connected with the retaining wall) but just can’t get the worry out of me about this wall.

Thanks for reading this far, any advice would be beneficial.

Ashington Homes · Feb 18, 2024 12:25 pm

Hi Sammy

It would be great to see some photos if possible, but if your wall is simply concrete sleepers with steel posts ( which sometimes do flex a bit) I wouldn't be overly worried about not having drainage behind it as they are not waterproof and any build up of water can be relieved via the face.

I would put it as a defect so there is a record but you are fine to move in. If it was my home I honestly wouldn't care as I have seen heaps of concrete sleeper retaining walls built with no drainage and years later they are fine, including my neighbours who had the sketchiest landscaper ever and I was certain the retaining wall between our properties wouldn't last a year but 5 years on it is still working perfectly.

So my conclusion is that concrete sleepers are pretty robust.

Cheers

Simeon

building-expert · Feb 18, 2024 6:44 pm

What state are you in?
Retaining wall is a structural element, designed by a structural engineer and should have been built in accordance with the approved plans, no excuse.
Retaining walls can fail suddenly and can potentially be a risk to life and injury.
I would be concerned about lack of drainage and the Geofabric on the wrong side could lead to water retention and soil liquefaction.
Hydrostatic pressure of wet soil is two and a half times that of water hence it may push the wall over.
About ten years ago I inspected poorly built retaining wall about 3 m high, I reported it as risk to life, not long after it collapsed without a warning about three minutes after a car pulled out of the way.
Regardless of what the builder and the engineer say, you are entitled to have your wall built in accordance with approved drawings, nothing less.
I would rise the matter with the relevant building surveyor, and yes a retaining wall not built in accordance with approved drawings is a major structural defect.
Were the wall to collapse, and there is injury or death do you thing that the builder and the engineer will put up their hand and say, yes it is my fault? They will do their best to make it your fault.

Sammy82 · Feb 19, 2024 12:16 am

building-expert

What state are you in?
Retaining wall is a structural element, designed by a structural engineer and should have been built in accordance with the approved plans, no excuse.
Retaining walls can fail suddenly and can potentially be a risk to life and injury.
I would be concerned about lack of drainage and the Geofabric on the wrong side could lead to water retention and soil liquefaction.
Hydrostatic pressure of wet soil is two and a half times that of water hence it may push the wall over.
About ten years ago I inspected poorly built retaining wall about 3 m high, I reported it as risk to life, not long after it collapsed without a warning about three minutes after a car pulled out of the way.
Regardless of what the builder and the engineer say, you are entitled to have your wall built in accordance with approved drawings, nothing less.
I would rise the matter with the relevant building surveyor, and yes a retaining wall not built in accordance with approved drawings is a major structural defect.
Were the wall to collapse, and there is injury or death do you thing that the builder and the engineer will put up their hand and say, yes it is my fault? They will do their best to make it your fault.

Thanks for your reply! All valid points and I agree with you on many of them. I am in QLD, any recommendations on a construction lawyer would be helpful