Kitchen and bathroom sinks fail differently
A kitchen sink blocks because fat cools. It goes down warm and liquid, sets on the pipe wall as it cools, and then catches coffee grounds, food particles and detergent solids until the bore closes. The deposit is firm, greasy and builds from the pipe wall inwards.
A bathroom sink blocks because hair binds with soap into a dense mat, usually sitting in the trap or just past it. It is a different material needing a different tool, which is why it is worth telling us which one we are coming to.
Why a slow sink is worth dealing with
Water rising in the bowl before it drains means the restriction is already there. Nothing about that improves on its own, and the cost difference between clearing a slow sink and clearing a fully blocked one, after it has backed up into a cupboard, is considerable.
Long shallow waste runs make it worse and are very common in London. Any kitchen or bathroom that was moved during a refurbishment usually ended up with a longer run and less fall than the original layout, and those runs collect residue far faster.
How we clear it
- Isolate and clear the trap, protecting the unit below
- Clear the waste run to the point where it joins the stack or the outside gully
- Check any other fittings sharing that run
- Flush with volume rather than just enough to empty the bowl
- Explain what the build-up was made of, because that usually points at a simple change of habit
We carry replacement trap seals and connectors. A trap that has been taken apart several times over the years often needs replacing rather than refitting, and it is better to do that than to leave a joint weeping under a cupboard.
The outside gully matters too
A kitchen sink usually discharges to a gully outside. If that gully is silted up or its grate is blocked with leaves, the sink will keep backing up no matter what we do indoors. Checking it is part of the job, and it is also the one part of a drain anybody can inspect themselves: lift the grate and look for standing water.
What it costs
Clearing a blocked sink is a fixed £120 plus VAT, with no charge for attending. If the run turns out to be damaged rather than blocked, or if the real answer is that the pipework needs rerouting because it was never laid with enough fall, we will explain the options before doing anything beyond the clearance.