Hi, I hired a company to replace the old retaining wall in our garden and agreed on payment upon completion. The wall they built is a thickness of one concrete block (100mm), about 90cm high, 3-4m long and holding back about 5m of soil on a slightly sloping garden. I'm worried it's not safe and won't last very long so I have asked another tradesman (recommended by a neighbour) to inspect it until I pay for the job. When I told this to the company they became aggressive, raised their voices and called me names that can't be said here. Do I have a reason for concern over the wall integrity and what are my rights here re: payment?
Edit: they built no footing/foundation and no drainage.
Are you a tradesperson and able to answer this question?
This should have been done by lay flat blocks, this would be the stronger structure, the wall should not be 100mm as you are relying on a single skin of blocks to support the soil behind. I would do as you said and get someone else around to look at the wall and give their opinion. This should have been done correctly in the first place. My personal opinion if you feel the wall has been done incorrectly and you have someone else's professional opinion I don't see why holding their money until it is corrected is a bad thing. Only problem is they may not come and correct it and they may just cut their losses.
There are lots of rules of thumb regarding thickness of retaining walls. For one example the wall thickness at the bottom is 1/3 of the height so 900mm high = 300 wide, 600mm high 200mm wide. As you can imagine this makes construction of any retaining structure expensive.
Also some weep holes at the bottom of the wall, and backed up with shingle, so water stays clean from soil that will run through those weep holes, especially with 5 m of soil behind it, and definitely nine inches not four inch brickwork and Piers that is not strong enough
Hi, I would have started with a concrete block laid flat and a face brick in front of that.After X2 courses of facework I would have used weep holes to help get rid of water build up behind the wall. The two walls could be tied together at usual intervals ie after six courses using steel ties horizontally..
Once the required height is reached the wall would need capping to prevent the wall from disintegrating year on year.
Before backfilling I would put 225 mm of pea gravel at the back of the wall covered with plastic to prevent the gravel from becoming polluted as water washed through the soil. This prevents water build up behind the wall as it would escape through the weep
Eyes!
Finally I would backfill with soil a couple of days after curing of the mortar.
This should have all been made clear in a detailed quote and agreed upon prior to work commencing.
These sort of projects are not cheap but the work involved needs clearly explaining to the customer first
