DRAINAGE DEVICE EMBEDDED IN A CONCRETE SLAB FOR MOISTURE DRAINAGE

摘要

A drainage device for drainage of moisture which collects between a waterproof isolating layer applied to the top surface and a concrete slab itself and/or moisture which passes through a surface layer deposited on top of the isolating layer. The drainage device has a drainpipe extending through the concrete slab and having at its upper end a shallow funnel provided on its upper surface with radially extending grooves and being flush with the top surface of the concrete slab. The funnel is fitted on its underside with a centering cuff concentrically surrounding the funnel tube spatially separating the funnel tube from the drainpipe, the diameter of the funnel tube being at least about 20% smaller than the inner diameter of the drainpipe. The upper end of the funnel opening is covered with a mushroom shaped insert resting on the top of the isolating layer and having radially extending grooves on its underside. The bottom end of the drainpipe has an outlet member supported in the concrete slab in such a manner as to be flush with the underside of the slab and has two concentric drip collars. The drainage device of this invention reduces clogging due to accumulation of lime deposits and reduces long icicles forming at the outlets of such prior art drainpipes.