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Basement & Foundations

Bituminous self-adhesive membrane system (SAM)

water load type according to en 13969 and en 14967

If you’re pressed for time and need quick results, our innovative BT 21 (BT 18) is the right product for you. The cold-bonding and self-adhesive bitumen waterproofing membrane requires no curing time at all.

A further advantage: The self adhesive bitumen membrane provides additional protection in the overlapping area. Even if there are wrinkles in the membrane, moisture doesn’t stand a chance. The membranę is installed similarly to wallpaper: Simply cut the strips to the required length and fix them on the primed surface with the needed overlapping.*


  • No curing time required
  • Immediately impervious to water and rain
  • Easy, fast and clean application
  • Innovative
  • Can be used down to -5°C (BT18 +5°)
  • Up to 50 % savings in time compared to thicklayer coatings
  • Allows immediate backfilling of the excavation
  • Tested for resistance to pressing water
  • Reliable solution with perfectly matched system components
  • BT 21 is radon proof


surface preparation

Waterproofing Systems, Bituminous self-adhesive membrane system (SAM), Substrate preparation

The substrates must be even, solid, load-bearing, dry or slightly damp and free of dust and substances which may impair adhesion (e.g. release agents). At low temperatures, make sure that the surface is free of ice.


Waterproofing Systems, Bituminous self-adhesive membrane system (SAM), Application

Apply a full-surface priming coat on the prepared external basement walls using the adhesion-promoting and solvent-free BT 26 Primer. Allow to dry. After drying, the primed surface remains slightly tacky. Now proceed by sealing the critical areas where water may penetrate, e.g. corners. Now cut the BT 21 Waterproofing Membrane to size. Before fixing the strips, seal the corners. After that, start by fixing the membrane cuttings to the base slab. Then proceed by covering the walls, strip by strip, with an overlap of 10 cm in the seam area. Before overlapping two strips, make sure to remove the red protective strip from the lower one. Without drying time, BT 21 is immediately impervious to water and rain – not a single second delay. There simply is no faster way! The upper edges of the membrane strips must be additionally protected to prevent water from seeping behind the strips. The upper edge of the membrane should be mechanically fastened using metal flush-mounted or plinth strips.

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