Cavity Drain Membranes
The Cavity Drain Membrane system is a special high performance polyethylene membrane which is extruded into a series of studs. The purpose of the studs is to create a continuous air gap behind the waterproof membrane. On the face of the membrane a welded mesh allows plasters and renders to bond efficiently to achieve dry and durable finishes.
The Cavity drain membrane is watertight, resistant to high and low temperature extremes, chemically resistant to acids, alkalis, oil and solvents and is approved for use in drinking water applications.
The membrane stud design provides a continuous air gap which serves two purposes. Firstly to isolate the damp wall from the new plaster and decorative finishes and secondly to allow ventilation of the wall for permanent dampness control.
Cavity drain membranes provide an alternative to conventional cementitious tanking systems, which work by holding the water back. Cavity drain membranes work on the principle of allowing water to continue to penetrate the structure but control it in the air gap and divert it to a suitable drainage point.
This extremely effective system utilises an ‘egg box’ style design, cavity drainage membrane. The membrane allows any water penetrating through the fabric of the building, to flow in a controlled manner behind the final wall covering, into concealed irrigation channels and thereafter into a sump. The water is then pumped into standard drainage exits.
In properties that have been flooded or are at risk of flooding a submerged sump pump would be installed below floor level to collect water penetrating through the walls/floor and pump it outside to an external drain.
The damp proof membranes that are used have molded studs on the reverse side to give clearance between the membrane & wall /floor to allow water to drain away freely.
It is important that when the waterproofing system is designed for your property suitable ventilation is considered i.e. natural ventilation or an extractor fan or other appropriate ventilation equipment. Without these measures being fully considered condensation is likely to occur.
The work is completed with the floor having a concrete screed or tongue and groove flooring installed and the walls having plasterboard and skim applied. This solution will provide a dry internal floor and wall surface, making the cellar or basement rooms of your property habitable again.
The above membranes can be used on properties where the walls are above ground but have been subject to major flooding. This allows the property to be re-occupied sooner than the normal drying periods allow. We are also able to offer cementitious tanking as an alternative damp proofing solution.