Pre-fabricated waterproofing membrane made of distilled bitumen and elastoplastic polyolefin polymers (APP) having a woven non woven single strand composite polyester reinforcement, which provide the membrane with very high mechanical characteristics and excellent dimensional stability. The excellent and long lasting performance of ULTRATEC ANTI-ROOT are given by the sum of the characteristics, the reinforcement and the waterproofing mass, opportunely added with a special chemical product (Preventol B2 Bayer) which confer a very high resistance to both root penetration as well as aggressive chemicals such as fertilizers, herbicidals, etc. The “anti-root” resistance of the material does not in any way affect the plants. The anti-root additive is not in anyway washed out of the compound and resists the heat of the open flame torch during application, therefore the product performs it’s function in a permanent way. Due to the characteristics, the membranes of the ULTRATEC ANTI-ROOT series are used with success for the waterproofing of both civil and industrial works where it is necessary to prevent the aggression of plant growth which may damage the integrity of the waterproofing layer, for ex. roof gardens, parking lots and underground works, retaining walls, flower boxes, etc.