Slow draining sink

A slow draining sink is one of the earliest warning signs of a developing blockage in the waste pipe or trap beneath the basin. The most common causes are accumulated soap scum, hair, toothpaste residue and food fats that gradually narrow the bore of the pipe. In kitchen sinks, congealed cooking fat is the dominant culprit, while bathroom basins typically suffer from hair and personal care products. Building Regulations Part H1 requires waste pipes of appropriate diameter and gradient, but even compliant installations accumulate deposits over time. Engineers usually address common causes by removing and cleaning the trap, then rodding or jetting the branch pipe if needed. If the issue affects multiple fittings simultaneously, the problem may lie further downstream in the main drain run rather than at the fitting itself.