CM Plaster Waterproofing Membrane - 40M²

CM Plaster Waterproofing Membrane - 40M²


  • £168.86

The Wykamol range of cavity drain membranes are high quality waterproof basement tanking materials giving a wide choice of stud height (drainage capacity) and plaster finish (dry lining or wet Plaster). For use on walls, floors, vaults and tunnels with minimal surface preparation required. Also suitable for external foundation waterproofing and to provide insulated dry lining for walls above ground level which may not be suitable for conventional plaster finishes.

Wykamol CM membranes are suitable for use in type ‘C’ (drained protection) structural concrete constructions in accordance with BS 8102:1990, Clause 3.2.4

Wykamol CM Plaster is a specialist wall membrane for basements and other damp surfaces giving a low-medium drainage capacity (1.84 litres/m2). The 5 mm studs are uniquely designed so that, when the membrane is fixed using CM Plaster Plugs, the walls can be plastered using conventional methods or ‘dot and dab’ plasterboard finishes.

In basements, CM Plaster can be used in combination with CM8/CM20 on the floor. Above ground, the low stud height enables CM Plaster to be used as a remedial re-plastering system following insertion of a DPC where it is necessary to match-up to retained plaster at higher levels. Alternatively, in walls severely affected by damp/salts to a high level CM Plaster can be used as a full-height damp proof membrane on walls (‘ventilated system’, see below). When using CM Plaster all lap joints must be sealed with CM overseal fibre tape.


Wykamol membranes provide a gas barrier system by the creation of an air gap when the studs of the membrane form a cavity within the building which allows the gas to flow freely beneath them to an extraction point.  When dealing with gas situations it is imperative for all joints to be sealed with care.  It is recommended that Wykamol Tape be used for primary sealing, with Wykamol Overseal Tape as a secondary layer of sealing protection.

The installation of a specially calibrated positive pressure pump is needed to exhaust any gas that is contained behind the membrane.
Where a gas tight membrane is required which also forms part of the waterproofing system an additional sump system complete with an AMA Drainer 301 pump is required to remove water ingress collected by the system.

It is advised expert consultation and advice is sought when dealing with gas contamination issues.

Wykamol Plaster membrane has been successfully independently tested and accredited by the British Board of Agrément.

Technical Data

Sheet thickness:

Approx. 500 μm

Unit weight:

0.48 (CM8) – 0.95 (CM20) kg/m2

Compressive strength (3 mm deformation):

180 kN/m2 (CM8)

Deformation under long term loading:

max. 20% at 50 kN/m2 (CM8)

Working temperature:

–50° to +60°C (all CM products)

Softening temperature:

+125 °C (all CM products)

Linear coefficient of thermal expansion:

0.13 mm/m. °C

Water vapour resistance:

1800 m2.s.GPa/kg (CM8) or 350 m equivalent air

layer. 3500 m2.s.Gpa/kg (CM20)

Air gap volume:

CM Plaster = 1.8 l/m2

Thermal resistance:

CM Plaster - 0.10 m2. K/W

Life expectancy:

at least 50 years


CM Plaster - clear

Chemical Resistance:

The product is resistant to all chemicals to which it can be exposed in normal building construction. A small number of aggressive chemicals (e.g. solvents) can, in large concentrations, damage the products during prolonged exposure. For special applications contact the Wykamol technical department for advice.


CM Plaster – 2.0 x 20m

* including flat overlapping edge (flange) without studs,

working area ca. 40 m2.


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