Techfol Dren

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Is a series of drainage geocomposites with Filtration + Separation + Drainage capabilities. The specificity of these geocomposites lies in their thickness/height (the height of dimples is approx. 20 mm), so an amount of more than 12 l/ms of water can be drained. These products, as well as our Drenfol or Drentextile drainage geocomposites well-known on the market, are designed to drain groundwater or rainwater to further drainage systems, thereby protecting civil engineering structures, bridge and tunnel abutments, against moisture and damp. The design of the geocomposite is based on a dimpled geomembrane being a synthetic barrier and a geotextile layer combined with it.

Estimated mass per unit area of the combined geocomposite results from the combination of the geomembrane of a mass per unit area within the range of 600 to 1000 g/m2 with the geotextile of a mass per unit area within the range of 90‑1000 g/m2. Rigid dimples reinforced with “ribs” provide very high compressive strength in relation to their height.

Installation Method

Geocomposite is supplied in rolls. Its installation is done by proper laying on the protected surface. The geocomposite sheets shall be overlapped. To make the overlap, you shall separate the geotextile and, after having the overlap made, re-bond it. Each of joined sheets shall overlap by a minimum of three row of dimples. To obtain a tight seal joint of sheets, a minimum one path of butyl tape cab be placed within the overlap area. The geocomposite shall be laid with the geotextile toward the water inflow (outside of the protected structure).

The installation process shall be scheduled in such a way as to reduce the number of punctures through the geotextile and geomembrane. Places of punctures through the geomembrane shall be sealed, for example, with butyl tape. Places of punctures through the geotextile shall be sealed by sticking a proper “patch” using a piece of the geotextile. The geocomposite can be laid along as well as across the covered surface without losing its hydraulic and mechanical properties. Before laying the geocomposite, previously completed construction works have to be accepted, for example, damp insulation, rain water collecting system, etc. When using our geocomposites, always follow the installation guidelines contained in the work technical design.

Transport and Storage

TECHFOL DREN geocomposite is supplied in rolls, rolls are secured and labelled, and CE marked. During transport and storage, the product should be protected from mechanical damages and high temperatures. For longer storage periods, membrane rolls shall be stored upright and protected against sunlight.

Documents to download

In order to obtain a document for a previous version, please contact us at the following address: