Delta's Type C cavity drainage waterproofing system comprises a cavity drain membrane, drainage system, package pump and control system. It is a maintainable basement waterproofing solution for new-build basements, refurbishment and retrofit projects.

Type C waterproofing is defined as “drained protection”, where the structure itself provides primary resistance against water penetration and incorporates a drained cavity system within the basement structure. 

Delta's internal membranes are used as a Type C waterproofing system forming a waterproof barrier as well as adequately draining the water to a suitable outlet, in most cases a sump pump drainage system.

Key features

  • Allows moisture or running water to travel behind the membrane within a controlled drainage system

  • Protects property against the damage of water ingress caused by hydrostatic pressure (groundwater pressure)

  • Protects against rising damp as well as being gas proof

  • Requires minimal preparation and disturbance to an existing substrate

  • British Standard 8102:2009 (BS8102:2009) ‘Code of practice for protection of below ground structures against water from the ground’

  • 30-year product guarantee, when installed by one of Delta's registered installers

  • Quality manufacturing system to ISO 900

Before a cavity drain membrane is laid or fitted on walls and floors constructed of new concrete, the concrete surface should be treated to reduce the risk of leaching of free lime and/or mineral salts and to avoid the obstruction of the drainage system. This can be achieved by using Delta's Polysil TG500 anti-lime treatment.