Useful26 Jun 2026ПроКанал ЕООД

Bathrooms and cloakrooms: how to avoid a hidden leak

Practical habits for the bathroom and WC that prevent the most expensive failures — and the signs that mean it is time to measure.

The bathroom and the WC are the busiest rooms in a home, and the only ones where water runs several times a day against waterproofing laid once, years ago. It is no accident that most leaks to the neighbours start there.

The cistern — the quiet consumer

A leaking cistern is the most underestimated water cost in Bulgarian homes. When the seal passes, the water runs straight into the drain — silently, invisibly, around the clock.

The check is elementary: put a few drops of food colouring in the cistern and do not flush for half an hour. If colour appears in the pan, the seal is passing. Replacing it costs less than one monthly water bill.

Silicone and grout are not forever

The silicone around the bath, the shower tray and the basin lasts between three and five years. After that it shrinks, cracks and lets water underneath — precisely into the zone hardest to inspect. The same applies to the grout between tiles.

Darkened or crumbling silicone is replaced, not cleaned.
Grout that crumbles under a fingernail is no longer a barrier.
Mould on silicone is a sign of constant damp beneath it, not only on it.

Ventilation solves half the problems

A good share of the “leaks” we are called to turn out to be condensation. A room with no ventilation, in which four people bathe daily, produces enough moisture to grow mould on the cold walls — without a single fractured pipe.

If the damp is even across a whole cold wall and worsens in winter, it is probably condensation. If it is localised and does not change with the season, it is probably a leak.

The difference is proved by measurement: the moisture meter shows whether the damp is at the surface or coming from the depth of the structure.

Signs not to wait on

A patch on the ceiling of the neighbour below.
A tile that sounds hollow or has lifted.
Constant damp at the base of the wall behind the WC.
A smell of mould that returns after cleaning.
A water bill that grows without explanation.

What follows

Diagnosis is non-destructive: a thermal camera, a moisture meter and, where needed, a CCTV survey of the waste pipe. You leave with a report saying exactly where the problem is — and that is the difference between a broken grout line and a broken bathroom.

See hidden damp detection, or book a visit.