Guys, as per the designed wall in my drawing, the contractor mentioned he’s going to lay a high load DPC. I would expect this to be in line with the existing DPC which would mean it would need to be partially under ground on the retaining wall by 300-400mm.
I believe to appropriately waterproof it, is to apply tanking slurry between the top of the foundations, the retaining wall up to ground level, French drain near the top of foundations, and tanking slurry just around the corner. Have a layer of tanking membrane leading to the French drain.
Generally the DPC layer is 150mm above GL. Understandably, we can’t split the DPC to different levels as that will just let moisture through?
Therefore we need to apply dpc to prevent rising damp from the ground, and tanking to prevent penetrating damp/moisture from the retained soil. Am I correct in thinking we need to make sure that the tanking slurry should at least go up to 150mm off GL, then have the wall rendered with sand & cement & plasticiser?