Kontract 20

Kontract 20 - 40M²


  • £256.69

Cavity drain membranes, drainage and accessories for remedial interior isolation of damp above-ground or basement walls and floors and direction of surface water.

  • Water entering through walls is contained behind membranes and directed to drainage at base of wall.
  • Suitable to provide Type C drained protection to Grade 3 or Grade 4 environment for residential or commercial use, in conjunction with adequate heating and ventilation.
  • Requires sump and pump or equivalent passive water disposal system. (Sumps and pumps specified separately).

Roll Size: 2m x 20m

Guidance for Kontract Interior Waterproofing System from Preservation Supplies


Kontract 20:

  • HDPE. High density polyethylene with 20mm height moulded compression studs.
  • Compression (maximum): 180 kN/m².
  • Suitable for basement walls or floors with active water penetration.
  • Fixed to walls at 450–600 mm centres by drilling through membrane studs and inserting brick plugs.
  • Horizontal laps: Overlap by three studs and seal with Rope seal. Vertical laps: Overlap flange area and seal with tape.
  • Above DPC level, leave 20 mm gap to bottom of wall membrane and 10 mm gap to top, as ventilation for water vapour. Insert profile strips into applied finishes or offset skirtings and covings.
  • Walls typically finished using dry lining. (Dry lining specified elsewhere).
  • Loose lay to floors with studs down. Seal flanges using tape. Seal other edges using Overtape.
  • Floors can be overlaid using expanded polystyrene insulation with T&G floorboards, conventional screed or anhydrite screed. (Floorboards or screeds specified elsewhere).


We Also Recommend