Synthetic EPDM impermeable membrane produced for Hydroidea with Firestone Giscolene™ L is an innovative product that was created to securely isolate water reservoirs: natural ponds, swimming pools, decorative ponds, and agricultural reservoirs. It is also perfect for covering compost or temporarily securing crops against unfavorable weather conditions. The membrane, due to its chemical stability, is environmentally friendly and safe for aquatic fauna and flora.


Artificial bodies of water that use natural methods of water filtration require good isolation from the ground. The stability of the most important water parameters, and hence water quality, depends to a large extent on this isolation. The Hydroidea EPDM Giscolene™ L 0.8 mm membrane provides a chemically inert liner that does not disturb the natural biological balance of aquatic ecosystems which is consistent with the idea behind ​​ecological ponds, swimming pools, and similar water reservoirs.

Forms to the ground

Hydroidea EPDM Giscolene™ L membrane can be used on many differently shaped substrates due to the exceptional flexibility of the material. The membrane can stretch over 300% in all directions (without cracking) and its flexibility is maintained to temperatures as low as -45° C, regardless of its age. The chemical composition of EPDM Giscolene™ L makes the membrane resistant to UV radiation, ozone, microorganisms, and unfavorable weather conditions. In addition, it does not contain plasticizers and antioxidants that affect the aging of the material. When exposed to extreme temperature changes (-45º C to 120º C), and harsh weather conditions, it retains its physical properties for decades, whether exposed or covered. What’s more – the membrane does not require maintenance and servicing. Water reservoirs that used Giscolene™ for isolation more than 30 years ago are still in perfect condition despite the passage of time.

Convenient sheets and quick installation

Hydroidea Firestone Giscolene™ L isolating membrane sheets are manufactured in a practical size for easy installation in water reservoirs. The membrane can also be ordered to measure, and adapted to the requirements of a specific project, which further improves it effectiveness. In this situation there is no need to make connections on site, so specialized tools and machines are no longer needed during construction. More complex details (e.g. tube flashings) can also be easily sealed.

Manufacturer certificates and experienced

Hydroidea Giscolene™ membranes have received CE certification and is a product tested by certification institutions such as the French ASQUAL. It is manufactured in the Firestone Building Products production plant (Terrassa, Spain), which is ISO 9001 and ISO 14000 certified, and has over 100 years of experience in the production of rubber products. The plant has been operating since 1903, when Harvey S. Firestone founded Firestone Tire & Rubber. Back then, the factory supplied tires for the first mass-produced cars in the US. Over the decades, Firestone has grown into a world-class organization, producing a wide variety of rubber products. Today, the Firestone brand is recognized around the world as a symbol of quality and innovation.


Technical specification of Hydroidea Giscolene™ L EPDM isolating membrane:


  • Standard commercially available rolls:
    • thickness: 0.8 mm
    • length: 30 m
    • width: 6 m and 9 m

  • Custom made EPDM rolls:
    • thickness: 0.8 mm; 1.0 mm; 1.1 mm; 1.2 mm
    • length: max 60 m
    • width: a multiple of 1.5 m (e.g. 18, 21, 46.5 m, etc.)

Other dimensions or ready-made sheets adapted to the design of the reservoir are available on request.
EPDM Giscolene™ L geomembrane  – binformation brochure – PDF