Water-proofing device for sealing construction pit to receive drained vertical sand filter to treat wastewater from sewerage installation installed in residential building, has waterproof-piece coating unit attaching side walls of pit

摘要

The device (12) has a waterproof-piece coating unit (17) formed from a geo-membrane, where the unit is provided to attach side walls (13) on a portion of a construction pit (11). The unit is placed between a geo-textile layer (16) to separate the unit of the pit and another geo-textile layer (18) forming a protection against puncture. The unit is provided with an edge (171) and another edge (172) that is adapted to extend out of the pit and provided with an inner contour (173) of identical dimensions to an upper contour of the pit. An independent claim is also included for a method for manufacturing a water-proofing device for use in an excavation for receiving a vertical sand filter to treat wastewater from a sewerage installation.