Wykamol CM membranes are manufactured from high quality (‘virgin') polymers - polyethylene (CM20, CM8, CM Plaster) and polypropylene (CM Floor) - all giving extremely low vapour permeability and high resistance to salts etc. Studs are formed in a regular pattern on one side to provide a range of drainage capacity options (see product specifications below). Wykamol CM Plaster studs are designed to provide a key for subsequent plastering (when used with Wykamol Plaster Plugs).

Wykamol CM8 is a medium capacity drainage membrane (4 litres/m2) for floors and walls both above and below ground level. When used on basement floors it is recommended that perimeter drainage channels are provided to optimise the flow of ground water towards the sump location.

The recommended plaster finish for the above systems is dry lining on stud framing (timber or metal) fixed to Wykamol Brick Plugs. Alternatively, plasterboard can be erected using ‘dot and dab' methods using dab collars to provide a physical bond for the board adhesive (see ‘Finishing' below). For floors, standard screeds can be applied (50 mm minimum) or T&G chipboard etc. (12 mm minimum, with absorbent layer for sound reduction).

Finishing 

Stud frame: where this method of finishing is anticipated the brick plugs should be in a vertical line roughly corresponding to the stud locations and battens (min. 25 x 38 mm) fixed to the plugs using 6 mm bolts or No. 12 screws. If it is not possible to ensure a straight line for the stud fixings use e.g. ‘Gyproc' brackets to hold the battens in place. When fixing plasterboard ensure the screw depth does not perforate the CM membrane. On reasonably flat walls Wykamol Dab Collars can be used to provide a key for board adhesives. The collars, which incorporate a built in fixing plug going through the centre of the collar, are sealed as before with rope on the collar face rather than under the fixing plug head. The fixing collars are set out according to the width of the plasterboard to be used at centers not less than 600 mm.

CM Plaster (or CM8 with Dab Collars): use a board adhesive or bonding plaster/adhesive recommended by the board manufacturer in a conventional ‘dot and dab' application. Ensure at least 50% of the membrane surface area is covered by plaster adhesive and to a final depth of 8 mm. Provide temporary support to the boards at the bottom (25 mm) until the plaster has set.