DIY Doctor UK DIY Forums

Looking for advice on re-tanking a living room in a basement flat.

How far should I take the plaster back above/underneath the existing tanking line?

Will it be necessary to take the plaster off along the tanking line for the whole circumference of the room or only the areas affected?

Any other advice welcomed.

Hi, in a normal house the wall is usually tanked to about a meter high as water cant rise above 6/700 mm above ground level in most cases due to gravity. But a basement flat. Will be a different as your already below ground.
In a basement situation firms usually lay a concreate floor with a drain in the low point & let any water in behind a special wall membrane that looks like an egg box that comes in rolls about 25met long. So you end up with a small void in the walls & floor & diverting the water to the drain which either goes away with gravity or may have a pump with a float switch to pump the water away.
A basement is defiantly a specialist area & would recommend a qualified firm as it’s a question that will be asked when selling a basement flat & will need certification & guarantees., .

Hi

^^^ 'collectors' is correct, you would need a cavity drain membrane system with drainage i.e. sump pump.