Pre-fabricated waterproofing membrane made of distilled bitumen and elastomeric polymers (SBS). The versions P and PA have a woven non woven single strand composite polyester reinforcement, with high mechanical characteristics and excellent dimensional stability. The versions PA are self-protected on the upper face with mineral slates which reduce superficial heat absorption improving the durability of the membrane. The self-protected versions have a side selvedge of 10 cm and upon request a head selvedge of 15 cm, to improve adhesion between the sheets.