Water Coming Through the Ceiling? Find the Source

A ceiling is the underside of a floor void, and almost everything that carries water in a house runs through that void. Above a ground floor ceiling there may be a bathroom with a bath, shower tray, toilet and basin, each with its own waste and seals. There may be central heating pipes feeding the radiators, a hot water cylinder, or a cold water tank in the loft. In a flat, the floor above belongs to someone else. Rain can reach a ceiling through a cracked tile, a blocked gutter or a failed flashing. Each of these leaves a different mark and leaks at a different time.

The timing tells you a lot before we arrive. A patch that grows after someone showers or baths points to the bathroom above. A stain that spreads when the heating is on, with a boiler that loses pressure, points to a heating pipe. A patch that only appears after rain points to the roof or a gutter. A steady drip with nothing in use is usually a mains pipe, a tank or a cylinder. A brown ring with a dry centre is an old leak that has stopped or comes and goes. A patch that is still dark and wet is live.

We do not cut the ceiling at the stain. Water runs along joists and plasterboard before it drips, so the stain is the lowest point, not the source. Upstairs we dye test each bathroom fitting and scan the floor with the thermal camera for heating pipes and the spread of water. Moisture readings are taken above and below. Where we need to see, a borescope goes through a hole the size of a coin, so the rest of the ceiling stays intact. If the water is from a flat above we can show where it is coming in, which helps when speaking to the neighbour or the managing agent.

A bulging ceiling is holding water. Do not stand under it and do not press it.Keep everyone out from under it, put a bucket below if water is dripping, and call us rather than piercing or cutting it yourself. Then close the stop tap if the drip does not slow. A ceiling that is sagging and heavy can come down, so keep children and pets out of the room. Once the source is located we photograph it, record the readings in a written report for your buildings insurer, and repair the pipe or fitting if you ask us to.