Tanking treatment is a way of preventing water ingress by coating for sealing walls of building structures below the ground, this is to protect the internal surfaces from water penetration. To do this we use either a conventional tanking render system, or alternatively a tanking membrane system.
Ideally this treatment should last forever permanently stopping water from coming in as it settles like cement. However, there is no guarantee that it will not wear down overtime.
Damp walls are a common problem within basements and cellars because the earth surrounding the walls is usually saturated with water. When the water makes its way through the masonry and brickwork it will often carry minerals and salt with it which will in result damage any finishing touches you have made to the wall such as paint.
It is not just cosmetic issues like paint damage or patches of damp that can be seen from water ingress, it can also lead to black mould and dry rot.