Hydrotec since 1988
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Sealing of cisterns and basins

For a perfectly watertight cistern or basin

The collection and use of rainwater is ecological and economical. Using clean potable water to wash your car or flush the toilet is nonsense.

In the Flemish region and Brussels-capital, the installation or rehabilitation of a rainwater cistern has become mandatory when building or renovating a home. The Walloon Region does not require the installation of a rainwater cistern, but one in five municipalities requests it when granting a building permit.

At the private level, the collected rainwater can be used for toilets, for watering the garden, for washing your car or for various cleaning operations. With suitable filtration, rainwater can also be made potable.

At the collective level, rainwater can be used as a stock for firefighters. The cisterns sealed by Hydrotec at the Napoleon Museum in Waterloo or under the Golden Fleece complex in Brussels are of this type.

Where ?

This chapter concerns

  • rainwater tanks
  • amenity pools
  • storm basins
  • the fountains
  • swimming pools
  • wastewater treatment plants.


  • The cistern or basin empties and does not retain water.

Why do it ?

Whether it is for the recovery of rainwater, the approval of an outdoor fountain, a swimming pool or the need to create a water reserve for the use of firefighters, it is essential to ensure the correct waterproofing of all these works.

TheProcessing steps of the sealing treatment of tanks and basins


Emptying the tank


Stripping and preparation of the walls

and from the ground


Installation of Hydro + bevels

in all angles


Application of a first coat of water-repellent coating

on vertical walls


Application of a second coat of water-repellent coating

on the walls


Application of the water-repellent coating

On the ground