Pre-fabricated waterproofing membrane with the specific function of an absolute vapour barrier. The compound is made of distilled bitumen and elasto-Plastomers (APP type), reinforced with a rot-proof fiberglass mat and aluminium metal sheet that allows to obtain a barrier against the passage of vapour. The DIMPLED FACED VAPOUR BARRIER MEMBRANE on the exposed side features a series of embossed dimples (more than 1000 per m2), formed by a special heat activated compound which ensures a strong and durable adhesion to the insulating panels. The advantages of the DIMPLED FACED VAPOUR BARRIER MEMBRANES are basically those aimed at avoiding the use of oxidized bitumen and cold bonding substances (mastic, polyurethane glues) for the application and adhesion of insulating panels. The hot oxidised bitumen, in addition to being extremely dangerous (burns, fumes, etc.), loses in little time its adhesive capacity, exposing the covering to the known dangers due to the strength of persisting wind action and the deformations of the roof covering. In addition, the embossed dimples allow to smooth out any unevenness of the support (more compound on the side where the insulating is applied) ensuring perfect adhesion on the entire surface of the insulating panel.