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.
The composite roofing system including ASTROFLEX 4000 SUPRA as underlay and ASTROFLEX 5000 SUPRA as top layer has been tested and classified in category “EXT. F.AA”, in accordance with British Standard BS 476 Part 3:2004 “External Fire Exposure Roof Tests” (Report n°336035).
40% of the lower face is coated in relief with THERMOADHESIVE STRIPS, formed by a special “hot melt” bituminous compound of elastomers and tackifying resins. The strips are activated by light torching: the immediate adhesion to the substrate grants an easy and homogeneous “partially bonded” application upon the insulation board or concrete substrate. This kind of application, in fact, promotes the diffusion of any water vapour arising from the substrates, preventing the occurrence of blisters; the distribution of mechanical stresses and structural movements is also ensured. Side and head overlaps of Vapour Equalizing Base Sheet should be sealed by means of normal torching; the same for the subsequent “fully-bonded” application of the cap sheet layer.