Use our Baseline 20 mm cavity drain membrane to waterproof basement floors. The cavity drain membrane can also be used on tunnel walls which have a high volume of water entering the tunnel walls.
What is a 20 mm Cavity Drain Membrane?
The cavity drain 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.
Our 40 and 20 sqm tanking membranes are robust and durable. Baseline 20 membrane will last the design life of the building. HDPE is rot-proof and resistant to alkaline, 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 Cavity Drain 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 the membrane is lapped by a minimum of 3 studs. 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. Our Baseline 20 mm cavity drain membranes are BBA approved for Type C waterproofing.
We stock the Baseline 20mm waterproofing membrane in 2 m x 10 m rolls. The membrane is easy to cut and trim using a sharp blade. Twistfix offers expert advice on all our cavity drain membranes. You can buy them online at low trade prices.
|Baseline 20 Cavity Drain Membrane||Data|
|Water Void Capacity||>14.61 l//m²|
|Water tightness at 60 kPa||>24 hours|
|Working Temperature||-50°C to +80°C|
|Mean Compressive Strength||165 kN/m²|
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