drainage teradrain®

Approved by IDDRIM

Drainage plays a critical role in the stability and durability of structures. To create a drainage system typically involves transporting large volumes of expensive aggregates along with a geotextile filter and collector drains. Once these supplies have been coordinated, they must be applied in several time and labour consuming operations which are often weather dependent.

teradrain® is an innovative geosynthetic product which improves, modernises and facilitates the execution of drainage mats, trench drains and drainage blankets.

The teradrain® drainage system consists of a combination of geotextiles and a network of perforated mini-drains, in ready-to-use rolls. teradrain® filters, drains, collects and removes water, representing great progress by comparison with conventional solutions.

teradrain® divides up the drainage path length, to reduce it to half the distance between two mini-drains. The well known principle of dividing a big problem into small portions therefore solves it more easily! Whereas uniform drainage sheets or layers of stone have to accumulate and convey all the drained water toward the outlet, teradrain® concentrates its draining effect between the mini-drains. The flow collected by each mini-drain is then removed separately toward a main outlet. It is this principle that accounts for the great efficiency of teradrain®.

teradrain is used in all construction work that requires drainage as a replacement or supplement to conventional drainage bases consisting of aggregates, drains and geotextiles.



The water contained in the soil is filtered by the geotextile layers at the top of the product. Once inside the geotextile sheet, the water follows the easiest path in the direction of the greatest head losses, i.e. perpendicular to the perforated mini-drains. The ingress of water into the the mini-drains is instantaneous with a maximum head loss.

A length of only 30cm is adequate to collect the maximum flow in the mini-drains!

The perforation at the bottom of the grooves are optimised and the water flows toward the outlet via the mini-drains.


  • landfill / waste storage covering
  • drainage base for road backfill, roadbeds, sports grounds, soil consolidation and foundations (e.g. reservoirs, buildings)
  • as a drainage blanket / covering for embankment retention and stabilisation of landslides
  • reservoir embankments, dykes
  • vertical drainage barrier for pavement edges, back of retaining walls and reinforced soil masses
  • gas drainage


  • teradrain® is a complete drainage system, which advantageously replaces geotextiles, aggregates and drains and plays an effective separation and drainage role.
  • One truckload of teradrain® can replace 100 truckloads of aggregate
  • light-weight flexible rolls, teradrain® can be applied rapidly and easily to deliver optimal conditions on all sites
  • the joining of rolls is by thermal bonding using a simple hot gas gun to ensure the continuity of filtration and drainage
  • teradrain® is designed for optimal performance and long-term reliability, with filtration and flow capacities preserved in the long run under working loads
  • teradrain® protects the geomembrane liners against puncture
  • teradrain® is suitable for draining the base on slopes, thanks to its tensile strength
  • our technical department provides application advice and sizing calculations using our proprietary Drainsoft programme
  • teradrain® is designed to provide an optimal result thanks to an extensive product range adapted for each application
  • our supplies are covered by a recommended insurance company


teradrain® is a needle-punched nonwoven geocomposite sheet comprising one, two, three bonded sheets and incorporating a network of regularly spaced perforated mini-drains.

The product has obtained approval by IDDRIM, the institute for roads and mobile infrastructure.

A waterproofing film in polyethylene can be added to provide a water or gas barrier. The network of mini-drains of diameter 20 mm is regularly spaced within the sheet, with a density ranging from 1 to 4 drains per metre and a unit flow capacity of 720l/h vertically.

Installation technique

  • create a plan layout according to the drainage plan (location of drains, slopes etc)
  • teradrain is unrolled with the mini-drains oriented in the desired direction of drainage, generally downhill if the membrane is being laid on a slope and so as to intercept the main collection drains, trenches or ditches
  • prepare a flat, graded compacted base with no protruding elements
  • unroll the product on the ground with a pole passed through the reel, or by hand, or suspended from a lifting beam
  • the textile overlaps depend on the supporting soil: 30cm on a stable, graded soil or 60cm to 1m on a soft soil
  • the joins can be thermally bonded together
  • execute joins between the rolls and the outlets according to the diagrams below
  • cut the product using a cutting disc or scissors, wearing gloves

1.4.3 IDRIMM Table – Hydraulic characteristics

In-plane flow capacity under a unit gradient (NF EN ISO 12958):

The product is tested in the cross direction (textile without mini-drain) and production (in the direction of the mini-drain, with mini-drain) at 20, 100 and 200 kPa (foam/foam option).

The test is carried out on a sample with a perforated mini-drain placed in the centre of the cell in the longitudinal direction. The flow values ​​obtained correspond to the performance of the perforated mini-drain due to the contrast in permeability between the non-woven part of the geocomposite and that of the mini-drain.

The values ​​presented below are deduced by calculation from tests on specimens whose perforated mini-drain is placed in the centre of the cell in the longitudinal direction.

FDF 300 T1Sens Production avec mini-drainTolérance
Sous 20 kPa2,5.10-4m²/s- 7,5.10-5 (-30%)
Sous 100 kPa2,1.10-4m²/s- 6,3.10-5 (-30%)
Sous 200 kPa2,1.10-4m²/s- 6,3.10-5 (-30%)

Additional information

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