Waterproofing roofs with thin, single-layer synthetic membranes

Although they have been available in France for over 20 years, thin single-layer synthetic membranes are still considered to be new materials, and are the subject of Avis Techniques and a "technical specification for the installation of roof waterproofing using PVC-P single-layer synthetic membranes", although this document (CPT) only covers PVC-P membranes and ignores other possible membranes: polyolefins, EPDM and others. There is therefore no DTU for these single-layer membranes. European technical approvals do exist, however.

In France, 15% of waterproofing on flat roofs is currently carried out using single-layer PVC or EPDM rubber membranes.

The special feature of this type of sealing is :

• they can be fastened in three different ways: by gluing, mechanical fastening or ballasting;

• they are suitable for all load-bearing elements: concrete, steel or wood, including steep roof slopes.

All these aspects of thin single-layer membranes (PVC, polyolefins, EPDM and others) will be studied in this article.