Pre-fabricated waterproofing membrane made of distilled bitumen and special polymers (SAP) having a woven non woven single strand composite polyester reinforcement, which provide the membrane 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. DELTATEC membranes have a side selvedge of 10 cm to improve adhesion between the sheets.