Coney Hall Bedroom Ceiling Leak in Winter? Check the Loft

If an upstairs ceiling in a Coney Hall house starts dripping in a cold spell, look in the loft before you look anywhere else. It is nearly always a pipe that split when it froze and is now leaking as it thaws, a loft tank that has overfilled because its overflow froze, or a tank fitting that has given way. Turn the stopcock off, open the taps, switch off the lights in that room at the consumer unit, and take a torch up the ladder.

Why Coney Hall lofts are the weak point

Coney Hall was built from 1933 by Morrell Brothers on the old Coney Hall Farm, with around a thousand homes planned and the Kingsway shopping parade on Croydon Road following a couple of years later. The houses are recognisable at a glance: two-storey semis with bay windows and half-timbered gables, plus chalet bungalows where the bedrooms are partly in the roof itself.

The estate has a famous history of corner-cutting. In 1937 a Coney Hall resident went on a mortgage strike over the poor construction of his house, and the case fed into the Building Societies Act 1939. Most of those houses have long since been put right, but the design still leaves a cold roof space full of plumbing: a cold water tank, often a feed-and-expansion tank for the heating, and pipes running across the joists. In a chalet bungalow, those pipes can run in the narrow eaves voids right beside the bedroom walls.

What is actually leaking?

A pipe that split in the frost

Water in a pipe freezes, expands and splits it. Nothing comes out while it is frozen. When the weather turns and the ice melts, the split opens and water runs out across the loft insulation and down into the ceiling below. This is why so many ceiling leaks appear on the first mild morning after a cold week.

A tank that has overfilled

The loft tank has an overflow pipe that runs out through the wall or eaves. If the overflow freezes and the float valve sticks, the tank keeps filling, has nowhere to spill, and brims over the top.

A failed tank connection

Old tank fittings and plastic tanks become brittle in the cold. A connection on the side of the tank can crack or start weeping.

Not the loft at all

If the bedroom is next to or below a bathroom, check that too. A shower seal or a bath waste can leak at any time of year. But if it is January and the ceiling is under the loft hatch, the loft is the place to start.

What do I do right now?

1. Turn the stopcock off by turning it clockwise. In many Coney Hall houses it is under the kitchen sink, in the downstairs cloakroom or in the garage.
2. Open the cold taps upstairs and downstairs to drain the pipes and empty the loft tank.
3. Switch the electrics off at the consumer unit for the affected room, especially if water is near a light fitting.
4. Put a bucket under the drip and move the bed and anything valuable out of the way.
5. If the ceiling is bulging, keep everyone out from underneath and do not pierce it yourself.
6. Take a torch into the loft and look for wet insulation, a dripping joint or a tank that is brimming, without stepping between the joists.
7. Switch off the immersion heater if you have a hot water cylinder, so it cannot heat up while the tank is draining.

If a pipe is still frozen elsewhere

Once the leak is under control, other sections of pipe may still be frozen. Thames Water’s advice is to thaw them slowly with a hot water bottle or towels soaked in warm water, never a naked flame, and to run a dry cloth along each pipe before turning the water back on, so you find any other splits before they find your ceiling.

How do I stop it happening next winter?

• Lag every pipe in the loft, including bends, joints, valves and the overflow, with proper foam insulation.
• Insulate the tank with a jacket or insulated lid, and do not lay loft insulation directly underneath the tank: a little warmth from the bedroom below is what keeps it from freezing.
• Check the eaves voids in chalet bungalows, where pipes are easily forgotten.
• Keep the heating on low through cold nights rather than off.
• Open the loft hatch a little in a hard frost.
• Check the overflow runs freely and is not blocked by a wasp nest or ice.

The same thing happens on the other side of the borough, and our guide to a frozen loft tank in Farnborough or Chelsfield has more on thawing safely. More about BR4 on our West Wickham page.

What about the ceiling?

A ceiling that has taken water needs to dry before anyone can tell whether it can stay. Plasterboard that has sagged usually needs replacing; lath and plaster sometimes survives. Fix the pipe first, dry the room, and then decide. Photograph everything for your insurer, and our water through the ceiling page explains how that damage is handled.

Need a plumber now?

If water is coming through a bedroom ceiling and you cannot find or stop the source, Call 07868 281022. Tell us your postcode, where the water is showing, and whether the stopcock is off. We cover frozen pipes in West Wickham and Coney Hall, and we agree the price with you before any work starts.