I have built a thick retaining wall to replace a thinner one. The ground level is about 1m, but I have built it taller to block my neighbour as well.
Suddenly, after 40 years of no water coming through the THIN wall, a vast amount of water is coming through at just one point. It is about 2000 litres per day. Everything is pointing to it being malicious, but it may be too complicated to prove.
How can I put waterproofing behind this wall without taking it down? I have no access to the neighbour's property.
We took down the existing wall on our side. We then built the new wall row by row with the gravel behind as we went up. We did not put in weep holes as there were none on the old wall and there has never been a water problem. No land drain either as there was none before.
We are going to drill some holes through the new wall now to channel the water to a sump we are going to build.
Basically, we need some remedial solution to waterproof if possible. Ideally behind the wall on the mud side. But how to we get to it. Obviously we can try and get the gravel out, but how do you waterproof the back. We ideally need to stop this water as it is coming directly up to our house.