Use Wykamol CM 20 mm Hi-Viz cavity drain membrane to waterproof basement floors. The yellow tanking membrane stands out from black butyl tapes. The contrast makes the joint seals easier to check. 

What is a 20 mm Hi-Viz Cavity Drain Membrane?

The bright yellow membrane is an HDPE barrier with 20 mm stand-off studs at 50 mm centres. The stand-off studs create a drainage space to contain water seepage. The cavity beneath the membrane has a volume of 14 litres per square metre. The large gap is ideal when tanking floors prone to constant moisture intrusion or high water table levels.

The 40 sqm tanking membranes are robust and durable. Wykamol 20 Hi-Viz will last the design life of the building. HDPE is rot-proof and resistant to alkalies, bacteria and fungi. Use the membrane to waterproof basement floors and other below-ground bases that require a cavity drain system. 

How do you use 20 mm Hi-Viz Membranes to Waterproof Basement Floors?

Set out drainage channels. Fit sump chambers where necessary. Treat freshly laid concrete with an anti-lime sealer to prevent free lime from leaching. Lay the roll of the membrane as you would lay Lino. Overlap the joints using the 100 mm wide stud-free flanges or ensure a 3-stud interlock. Use waterproof tape to seal all joints and floor-to-wall junctions. Finish with a concrete pour or a 65 mm screed.

Type C Waterproofing with Cavity Drain Systems.

Basement waterproofing membranes form part of a sealed cavity drain tanking system. The system must manage and dispose of water behind the membrane as per BS 8102: 2022. The Wykamol CM 20 mm cavity drain membranes are BBA approved for Type C waterproofing.

We stock the yellow CM 20mm hi-vis waterproofing membrane in 2 m x 20 m rolls. The bright yellow tanking barrier lightens dim workspaces. The membrane is easy to cut and trim using a sharp blade. Twistfix offers expert advice on cavity drain membranes. You can buy them online at low trade prices.