The cavity drain system is one of the most commonly used methods ofÂ controlling waterÂ in basement projects. The cavity drain channel is utilised in association with the installation of a cavity drain membrane to the walls and floors. The cavity drain channel wouldÂ generally be laid around the ‘perimeter’ of the basement at the wall / floor junctions, this carries the water to the sump chamberÂ where it is collected and discharged using a sump pump or gravityÂ system to an external drainage point.
The sump chamber is installed below the finished floor level. Pipe work to carryÂ the excess water and electrical wiring for the sump pump is fitted in ducting before the concrete is poured.
Prior to theÂ installation of the new concrete baseÂ to the basement or cellar floor,Â suitable provision must be made for the installation of the drainage channel. This is normally achieved via the temporary installation of suitable size timbers or polystyrene etc being placed at the wall floor junctions where the cavity drain channel is to be placed. Once the concrete is laid and set, these temporaryÂ formers areÂ removedÂ to enable theÂ installationÂ of the cavity drainage channel.
Section of the drainage channel
In REFURBISHMENT PROJECTS the system is installed exactly as above following excavation and removal of the original floor etc.
The cavity drain system can be designed to suit various property layouts or building designs, on occasions various factors may result in a variation to the specification detailed above. Additional provision must also be made for flushing out / future maintenance of the system.
One of the range of Cavity Drain Membranes
Within the PLANS & DRAWINGS section of the website there are numerous cross section drawings detailing the above system.