There are two forms of dealing with below ground waterproofing. A cavity drain method which involves using a high density studded plastic waterproof membrane which acts as a dry lining to ceiling walls and floors. There is an air gap behind which allows water movement which is channeled into a drainage system which in turn drains to a sump pump with non return valves and then can be drained away from the building.Basement Waterproofing-Suska Damp Proofing
The membrane is fixed using waterproofed plugs and all joints are sealed using a waterproofed tape. The internal finishes to the membrane can be sand and cement rendered and left or finish plaster can also be applied. The most common finish is to dry line with plaster board and the floor either boarded or screed finished.
The alternative to cavity drain system is the tanking system, This involves coating the walls and floor in multiple coats of tanking solution. It is a simple method in which a waterproof mix is applied to the previously prepared surfaces to act as a barrier against dampness.