Structural Basement Waterproofing
If basement waterproofing is to be applied during the process of building development the structure will need to be surveyed to make known several areas. The intended use, the existing form (if any), the ground conditions including the water table and contamination and the suitability of the structure for the desired waterproofing system.
The British Standard BS 8102:2009 is the code of practice for protecting structures below ground level from water ingress describes three forms of structural waterproofing.
Basement Tanking (Type A)
Type A relies solely on a waterproofing membrane to stop water ingress and it has no integral waterproofing protection. This form is known as tanking and it provides protection against groundwater migrating into a structure by forming a barrier between structure and groundwater.
Structurally Integral Protection (Type B)
Type B is protection against water ingress which is provided by the structure through materials incorporated into the shell of the structure itself. Construction using reinforced water-resistant concrete or structural steel provides the protection in Type B systems.
Drained Protection (Type C)
This is an internal water management system in which the protection is allowing groundwater to penetrate the external wall, or floor, as far as the internal lining. This water is then collected via a Cavity Drain Membrane before diverting to a controlled drainage safe point ready for removal. Removal of the water is handled by either a sump and pump chamber or channeled away from the structure through passive drainage.