joint ouvert

CONT: Les joints ouverts des tuyaux sont entourés de matériaux filtrants [...] et recouverts d'un morceau de tuile ou d'ardoise pour éviter [...] l'introduction de la terre.

CONT: Joints and connections in the plumbing systems shall be gastight and watertight for the pressure required by test, with the exception of those portions of perforated or open joint piping which are installed for the purpose of collecting and conveying ground or seepage water.
CONT: It is desirable, in laying the tile, that the slope be between 0.1 and 0.3 per cent to give both adequate distribution and adequate time for percolation of water through the open joint in the line.