Quick answer
A dripping tap is a worn washer on older compression taps, or a failed ceramic cartridge on modern quarter-turn ones. A slow drip wastes roughly seventy-five litres a week, which is quiet money going down the drain. If a new washer or cartridge does not stop it, the seat the washer closes onto has been scored and needs re-seating or the tap needs replacing.
Common causes
- Worn rubber washer on a compression tap
- Failed ceramic cartridge on a quarter-turn or mixer tap
- Scored or corroded valve seat that a new washer cannot seal against
- Excessive mains pressure hammering the seal every time the tap closes
- Grit from municipal supply work lodged under the seal
- Over-tightening, which crushes the washer and accelerates the next failure
What you can do now
- 1Work out whether it is a compression tap or a quarter-turn before buying parts — they take completely different internals
- 2Close the isolation valve under the basin, or the mains if there is none, before opening anything
- 3Take the old washer or cartridge with you to match it exactly
- 4Do not over-tighten on reassembly; snug is enough, and force destroys the new washer
- 5If the drip continues with a new seal, stop — the seat is scored and needs a tool, not more force
When to call a professional
If replacing the washer or cartridge does not fix it, the seat is scored and needs re-seating or the tap needs replacing. Call sooner if the tap is on a hot line, since the drip is heated water. If several taps fail in a short period, ask for mains pressure to be tested — high pressure destroys tap seals across the whole house, not just one.
Typical cost in Johannesburg
Washer/cartridge replacement R350–R650
Indicative ranges only. We provide written, itemised quotes before any work.
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