A bath overflow is a secondary outlet at the upper end of a bath that drains water away once the level reaches a preset height, preventing flooding if taps are left running. UK baths must be supplied with an overflow as standard, with the combined waste and overflow assembly complying with BS EN 274. The overflow is connected to the trap below via a flexible pipe, joining the main waste outlet to share a single trap. The connection is sealed at the rim of the bath using a rubber gasket inside and out. Failure of the overflow seal is a common cause of slow leaks in older London bathrooms, often producing damp patches in the ceiling of the room below. Regular inspection and gentle tightening of the back nut can extend the life of the seal.
Bath overflow
Upper outlet on a bath that prevents flooding by draining away water above a set level.
