Slow draining bath

A slow draining bath usually points to a partial blockage in the waste outlet, trap or short branch pipe serving the fitting. The most frequent cause in UK homes is a build-up of hair bound together with soap residue, shampoo and body oils which forms a dense, fibrous plug just below the plug hole. Bath wastes are typically 40mm diameter with a shallow gradient under Building Regulations Part H1, leaving limited tolerance for restriction before flow slows noticeably. Engineers usually address the issue by removing the waste fitting and trap, clearing the plug mechanically, then flushing the branch pipe. Recurring slow drainage despite cleaning can indicate scale build-up, a low spot in the pipe, or a problem further downstream in the soil stack. A CCTV inspection helps confirm the cause.