FIELD: methods of roof drainage and roof drainage devices. SUBSTANCE: drainage device has trough made in roof structure, hole located at trough base, drain pipe connected with hole and means for changing open flow of water to closed flow when water flow rises. To strengthen the drainage, member regulating sectional area of drain pipe is installed in drain pipe, in throttle, after hole. Regulation is effected so that shape of sectional area of drain pipe remains practically invariable. EFFECT: higher efficiency. 10 cl, 6 dwg, 1 tbl
