High performance SBS modified bitumen base layer membrane, Preflex is specially designed to be used together with Graviflex cap sheet for green roofs, mixed-use terraces, car parks and podium / plaza decks. Polyester reinforcement provides high resistance to puncturing. Both sides are covered with thermofusible film.

Suitable for:

  • Waterproofing of green roofs and multipurpose areas with additional protection: extensive and intensive green roofs, planted areas, podium/plaza decks with access to pedestrians and light vehicles
  • Non-accessible exposed roofs: base layer with a granule-surfaced cap sheet 
  • Protected roofs such as gravel ballast, concrete slab for use as a base layer
  • Car parks with paving slab & planted areas: base layer with Graviflex cap sheet
  • Protection of foundation walls and below ground structures

Can be installed on:

  • Concrete and wood bearing elements with or without insulation

Use our solution guide to select the right system for your waterproofing needs.


Universal base layer for multi purpose use: podium / plaza decks, non-accessible or accessible roofs, car parks, leisure spaces
High mechanical and chemical resistance
Excellent durability with a long service life at least for 30 years
Continuous waterproofing system that can receive, juxtaposed, the direct application of all the corresponding additional protective finishes
Excellent sustainable credentials


Length (m) : 6.5 & 10 & 20 m
Width (m) : 1
Thickness (mm) : 3
Weight (kg) : ~25 & 38 & 75 kg