A Drained Cavity within the basement or sub-structure is the provision of a continuous pre-formed cavity, which intercepts and drains away water ingress in accordance with BS8102: 2009 Type C (Drained) protection.
There is a permanent reliance on this cavity to collect groundwater seepage through the structure and channel it to drains or a sump for removal. When selecting a suitable water management system, the external basement structure must provide enough resistance to water ingress to ensure the cavity only accepts a controlled amount of water.
Cavity Drain is a profiled HDPE sheet cavity former that provides a clear and safe route for water seepage into an existing or new basement. It also provides a vapour barrier, enabling this low risk form of construction to be used for all Grades of basement. Cavity Drain is installed inside the basement structure and onto the structural slab.
Facilities for inspection and draining ground water ingress must be incorporated into the design and this can involve the use of Aqua Channel at the wall/floor junction, or casting the structural slab to falls to direct water to pumped collection sumps and/or to gravity fed drainage systems.
Supporting Plaster and Render Finishes
Plaster Drain works on the same principle as Cavity Drain, but incorporates a surface designed to support plaster or render finishes. It is usually used where internal space is at a premium and a low level of water ingress is envisaged. It can also be used in conjunction with the larger Cavity Drain membrane on the floor, within a basement, as well as on damp walls above ground where it can be ventilated top and bottom. To find a suitable waterproofing solution for this or any application click here.
