Bitulen® SK374

What is Bitulen® SK374

Bitulen® SK374 is a self-adhesive 1.5 mm thick preformed waterproofing membrane for use in basements and substructures, to protect against water ingress.

Bitulen® SK374 comprises of cross-laminated SBS modified bitumen. The underside is protected by a silicone coated release paper.

Bitulen® SK374 meets the requirements of Singapore Standard SS 374:1994 for preformed sheet membranes.

Bitulen® SK374 provides an effective waterproofing membrane for foundations, tunnels, floors and flat roofs. Being cold-applied, it is ideal for installation in restricted and confined spaces.

  • Retaining walls, foundations
  • Foundations, tunnels, floors and flat roofs
  • For use both above and below grade with concrete, brickwork and blockwork constructions
  • High bi-axial strength cross-laminated polyethylene reinforcement film
  • Self-adhesive
  • Can be cold-applied
  • Underside protected by a silicone-coated release paper
  • Meets Singapore SS 374:94 standards
  • Excellent durability reduces future maintenance costs
  • Conformity to Singapore Standard SS374:1994

All surfaces shall be wood trowelled, free from dust or loose materials and dry. Where surface is not smooth, it should be rendered to provide an even surface.
All surfaces shall be primed with a bituminous primer and allowed to dry tack-free before the membrane can be laid. The membranes shall not be installed on site where the ambient temperature is below 5 °C.

After removing the release paper, the membrane is then pressure bonded to the primed substrate. Apply pressure from the centre to prevent air being trapped. All laps shall be 65 mm wide.

The membrane shall be protected with a layer of screed for the horizontal surface as soon as possible after installation. For vertical surfaces, the waterproofing membrane shall be protected by a 25 mm thick expanded polystyrene board before backfilling.

Care shall be taken so as not to damage the membrane after installation.

Test Method
Typical Value
1.5 mm
1 m x 20 m
Tensile strength
SS 374
>3.0 N/mm2 (long.)
>3.0 N/mm2 (trans.)
SS 374
>800% (long.)
>360% (trans.)
Tensile shear at joints
SS 374
Resistance to leakage at joints
SS 374
Hydrostatic test
SS 374
Water vapour transmission
SS 374
0.07 g/m2/hr
Water absorption
SS 374
Dimension stability
SS 374
0.06% (long)
0.08% (trans.)
Cold temperature flexibility
ASTM D5147
-30o C