ASTROFLEX 4000 SUPRA is a waterproofing membrane made of distilled bitumen modified with SBS (styrene-butadiene-styrene) polymers. The high grade elastomeric compound ensures great elasticity, ease of application and superior bonding and tightness of all joints and overlaps. ASTROFLEX 4000 SUPRA is ideally suited for systems where waterproofing layers are subject to structural solicitations and where superior ageing resistance and flexibility at low temperatures are required.

Thanks to its special formulation, ASTROFLEX 4000 SUPRA has specific resistance proprieties to external fire: tests performed by notified laboratories classify our membrane as Bʀᴏᴏғ(t2)-(t4) according to EN 13501-5.

ASTROFLEX 4000 SUPRA can be employed as:
- underlayer in double-layer systems Bʀᴏᴏғ(t2) or Bʀᴏᴏғ(t4)/FAA in combination with ASTROFLEX 5000 SUPRA;
- underlayer in double-layer systems Bʀᴏᴏғ(t2) in combination with ASTROFLEX 6000 SUPRA.

ASTROFLEX 4000 SUPRA is also designed for waterproofing vertical and horizontal substrates in contact with the ground, in order to protect the building interiors from the infiltration of Radon gas.