Waterproofing EPDM membranes

EPDM Membrane Application in the Construction Industry for Roofing and Waterproofing... 

EPDM membrane of 1.2 mm thickness is 22 times more waterproof than asphalt and 59 times as waterproof as PVC sheet. 

EPDM membranes can be factory assembled from smaller width sheets by a hot vulcanising process, using suitable rubber-based adhesive or room temperature vulcanisable adhesive system, to form a higher width waterproof joint surface. Alternately, the individual sheets can be welded at site with the help of a proper adhesive system. 

PVC and PE have played a major role in the shift of early roof waterproofing technology and materials. After the introduction of elastomeric and other thermoplastic materials, flexible membranes of polychloroprene (Neoprene) rubber, butyl rubber and Hypalon were used. Later on, liquid PU, solvent-based liquid acrylate and liquid EPDM systems, in addition to new materials like SBS modified bitumens, were also used in the management of roofing. All fall into the single-ply family of roofing, which offers a much cleaner, safer, energy-efficient and cost-effective alternative to built-up roofs. 

To meet these desirable properties, the appropriate polymer to consider would be ethylene - propylene-diene terpolymer (EPDM). In the manufacture of a cost effective, impermeable membrane system, EPDM rubber is the right choice as a discreet material for improved waterproofing and protective lining applications in roofing and other uses in the construction sectors [125]. 

Over time it is far more economical than traditional waterproofing systems. A single layer membrane of thickness of 1.2 mm made from EPDM rubber provides superior waterproofness than multi-layer traditional material systems. 

EPDM roof sheet is one of the lightest roof membrane materials because of its low specific gravity. It is highly suitable for lightweight structures and puts negligible extra load on the roof to be waterproofed. It is serviceable over a wide range of temperatures -50 °C to 150 °C, and the membrane does not embrittle in freezing condition nor soften in hot weather. 

In many countries asphalt felt coating is used to protect the building roof from leaking -the life of such a waterproofing system is only two to three years. For exceptional water and weather resistance the EPDM roof membrane is known to be serviceable for more than 20 years and virtually no maintenance is required. 

Ballasting is an economical and quick system to secure an EPDM roof membrane. Waterproofing sheet is simply fitted over the flat roof or to a low slope, and covered with cleanly washed well rounded gravel with a diameter of 40-50 mm. Corners may be ballasted with suitable concrete slabs to prevent the sheeting from wind uplift and the perimeter can be fixed with contact adhesive. 

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