Where do pipe leaks usually start?

Most leaks begin at a join rather than in the middle of a straight pipe. Copper pipes in a house are connected with soldered fittings, compression fittings with a brass nut and olive, or push-fit fittings, and each of these can loosen, corrode or fail over the years.

Typical places to look are:

under the kitchen sink and bathroom basin, where taps and waste traps connect
behind the washing machine and dishwasher, on their supply hoses
at the valves either side of a radiator
in the airing cupboard, around the cylinder and its pipes
in the loft, near a cold water tank
where a pipe passes through a floor or wall and has been rubbing

What is a pinhole leak?

It is a tiny hole worn through the wall of a copper pipe, often by slow corrosion from the inside. It may only show as a fine spray, a bead of water that keeps reforming or a green crust on the pipe. Pinholes in one place can be a sign that a longer length of the same pipe is thinning, which a plumber can look at while they are there.

How can I tell if a leak is hidden?

Water does not always appear where it escapes. It can run along a joist, soak through plasterboard or spread under a floor before you see it. Watch for a ceiling stain that keeps growing, skirting that has swollen, flooring that lifts, a smell of damp in one room or a hissing sound when nobody is using water.

If you have a water meter, it can help. Make sure nothing in the house is drawing water, note the figures on the meter, leave everything off for a while, then look once more. If the figures have crept up, water is escaping or being used somewhere.

What should I do while I wait for a repair?

Turn off the small isolating valve on the pipe if there is one, using a flat screwdriver to turn the slot across the pipe
If there is no valve, or it will not hold, close the main stopcock
Put a bowl or tray under the drip and move anything that could be spoiled
Keep water off sockets, switches and appliances, and do not touch anything electrical that is wet
Take photographs, which are useful for the plumber and for any insurance claim

If a ceiling is bulging with water, keep people out of the room beneath it. Call 999 if anyone is in danger.

Is a leak outside the house my problem?

It depends where it is. In England your water company looks after the pipe from the main in the street up to your property boundary, including the stop tap usually found near the boundary (Ofwat explains who owns which pipe). The supply pipe from there to your house is normally the owner's responsibility. A patch of grass that never dries, a wet path or a sudden drop in pressure can all point to a leak on that buried pipe.

A leak you suspect is under the road or footway is one for your water company to hear about. If it is inside your boundary, a plumber can trace and repair it.

What can a plumber do about a leak?

They will find the source first, which may mean lifting a floorboard or opening a boxed-in panel. Depending on what they find, they might remake a joint, replace a fitting or valve, cut out and replace a damaged length, or renew a perished appliance hose. They can also tell you whether the rest of the pipework in that area looks sound.

Drying out and redecorating are separate jobs. Wet plaster and timber usually need to dry fully before they are covered or painted.

What about leaks on heating pipes or near gas?

Radiator valves and heating pipework are plumbing, so you can enquire about them here. A leak from a boiler itself, or any work on gas pipes or appliances, is a job only for a Gas Safe registered engineer. If you smell gas, open windows, avoid switches and flames, leave the building and phone 0800 111 999, the National Gas Emergency Service number.

What details help the plumber?

your postcode
where the water is showing, and where you think it is coming from
whether you have managed to turn it off
whether it is hot, cold or heating pipework, if you know
the type of home: house, flat or maisonette
any damage already done, such as a stained ceiling

Who you will hear from

We pass your enquiry to one local plumber, if one covers your postcode. It is never sent to a list of companies. If nobody covers your postcode, we will tell you and will not pass your details on.