Basements- Waterprooofing options
BS 8102 also defines 3 Types of water-resistant construction;
A Barrier (Membrane) protection
The structure has limited integral protection and relies permenantly on a waterproofing membrane. The membrane must be able to cope with groundwater pressure plus any imposed or service loading or movements. The membrane can be appplied internally, externally or sandwiched between inner and outer walls.
B Structurally integral protection
The structure itself provides a water resistent shell. Typically reinforced concrete, the design must meet strict parameters. Note that cracking is unlkely to be avoided so some degree of water penetration is not uncommon.
C Drained protection
The structure provides primary resistence to water penetration but incorporates a drained cavity within the structure which is permenantly relied-on to collect and remove water.
These options can be combined e.g. Type A and B, A and C or B and C, depending on the risk of water penetrtion and environment required.
Ref: Basements: Waterproofing. General Guidance to BS 8102:2009, Basement Informtion Centre, Camberely, 2011