How to find and prevent a water leak in your house

22 January 2025

How to tell if you have a water leak

Water leaking in the house isn't something any of us want to experience, but it happens more than you think.

According to the Association of British Insurers (ABI), escape of water damage is one of the most common types of domestic property damage insurance claims.

EASY AS HACK

If you've got a water meter, check your bill for any sudden increases. If you don't know why the bill is so high, it could mean water is leaking somewhere.

AT A GLANCE

From damp smells to a slight dripping sound, you can spot a water leak in a few differenet ways.
To prevent damage to you home, it's crucial you know what to look out for and how to prevent leaks from getting bigger.
Here's everything you need to know.

common signs of a water leak

Quite a few signs indicate a water leak in the house. To prevent damage to your home and prevent wasting water, it’s essential you know what these signs are.

The most common signs include:

- A damp smell
- Mildew on the walls
- Wet or discoloured patches on the walls
- Warped floorboards
- Warped doorways
- A dripping sound
- Puddles or pooling
- Low water pressure

If you don’t see any of these signs but still suspect there’s a leak, you might need to look out for other signs. These include:

- Huge water bills – if you have a water meter, a sudden rise in your bill could be a sign that water is leaking from somewhere.
- Water discolouration – put food colouring in the cistern (or toilet water tank) and wait 10 minutes. If the water in the bowl is the same colour as the water in the cistern, there’s a leak.
- A constantly running heater/boiler – if your water heater or boiler is always running, this could mean there’s a leak in the hot water pipe.

how to find a water leak in your house

Look for the common signs listed above. Try to pinpoint the source of the leak by moving from room to room listening for running or dripping water.

Then, check for moisture on the walls, floors and ceilings or any unusual wet spots. Don’t forget to inspect the outside of your home as well – look for wet areas around taps, pools or hot tubs.
Consider calling a professional plumber if you think there is a leak in your home but can’t locate its source.

What are the main causes of water leaks in your home?

We’ve highlighted vital signs to look out for, but what could cause a leak? Here are some of the culprits:

Cracked sinks, tubs and tiles

If sinks, bathtubs or tiles are cracked, water can leak out, causing mould, mildew and rot. Cracks can occur due to frequent use, general wear and tear, impact damage, or corrosion.

Worn grout or sealant

Old grout or sealant in bathroom or kitchen areas can cause water leaks if it’s worn out.

Worn OUT SEALS

If the seals on dishwashers, fridges and washing machines become old, worn, or distorted, these appliances can leak.

A clogged drain

When a drain line clogs, the water has nowhere to go. Instead, the drain line fills up as more water is poured into the drain until it completely backs up. In some cases, a clog can even lead to a burst pipe.

CORRODED PIPES

Heating pipes can corrode and leak slowly. Look for the signs of rust on pipes and radiators and check joints for leaks.

Signs that the water mains pipe that runs across your property’s boundary may be old and corroded include pooling water and rust in the tap water.

High water pressure

High water pressure can add strain to your plumbing system, causing pinhole leaks and cracks and loosened joints.

tree roots

Tree roots can block or get into the pipes and joints in your drainage system; and use the water to grow. As the blockage increases, the pressure causes cracks in the pipes.

roof damage

Wear and tear, age, moss, debris, damaged lead flashing, broken tiles and slates, rotting membrane and underlay, blocked gutters, cracked mortar around chimneys, and badly installed skylights can all lead to roof leaks.

a toilet leak

The mechanical flush valve in dual flush systems is the most likely cause of a leaky toilet. The plastic or rubber seals can degrade or the fill valve or dual flush valve could be faulty. This is more likely to waste water than cause a leak.

What to do if you have a water leak in your house

So, you’ve found clear signs of a water leak (and, in some cases, the cause), but what do you do now?

To prevent further damage to your property, you should follow these 10 steps.

Check where the leak is coming from

If the leak is coming from the heating system or water supply, turn off the heating and water supply using the valve next to the boiler. Open the hot water tap to drain the system.
If the leak is from appliances, turn them off.

Leaks from broken pipes in the shower or from central heating pipes in underfloor heating systems may not be instantly visible. Consider calling a professional plumber to test and locate them.

You can use your water meter to see whether the leak is external. Take a meter reading, then turn off the stopcock and run your cold taps until they stop. Take another meter reading, then wait 15 minutes and read it again. If the meter readings differ, they may indicate an outside leak. If they’re the same, the leak is inside.
Turn off the water

The first thing to do when you’ve got a water leak is turn off the water using your stopcock. This will prevent more water from coming out.

The stopcock is usually located on the ground floor of your home, under the kitchen sink. Once you’ve found it, turn it off by turning it clockwise.
Contain the leak
Use buckets, towels, etc., to collect the water and prevent the water spreading further. You should also move furniture, appliances, electronics or other valuable items to avoid damage.
Run your taps dry

Run your taps to get rid of all the water in the system.
Turn off your electricity

You need to switch off electrical sockets, switches and lighting circuits to be on the safe side.
Call a plumber

Once you’ve prevented further immediate damage, or if you are struggling to detect where the leak is coming from, call a professional.
Contact your insurer

Call your insurer and let them know where the water leak is. Buildings insurance and Contents insurance usually cover water leaks, but check your policy for details.
Document the damage
Take photos of the damage to share with your insurance company
Dry the area and repair the damage
Open windows, use dehumidifiers, etc., to dry the area, and check for any signs of mould
Invest in a leak-detection

A leak detection device monitors your usual water use and turns off the water if it suspects a leak. You can get a plumber or a professional to install the device, which could help prevent lots of damage to your property.

How to prevent water leaks

You can’t always stop leaks from happening, but there are some things you can do to prevent them and combat wear and tear.

Keep your home in good condition. Have your boiler, heating and hot water system regularly maintained to make sure any issues are fixed before they get bigger.
Check the grouting and sealant around baths, sinks and showers. Sealants don’t last forever, so make sure you replace them and reseal the area before a leak occurs.
Maintain appliances like washing machines and dishwashers. Replace the water supply hoses if they are kinked or blocked.
Maintain your roof and gutters. Clean your gutters twice a year; more regularly if your house is near trees. Ask a roofing professional to check the roof yearly for damage, such as missing or broken tiles.
Maintain your drains. Stop blockages by not flushing fat, oil, food or grease down drains or wet wipes down the toilet. Add guards to plugholes, showers and outdoor drains. Use a plunger or a plumber’s snake to remove hair blockages, before trying chemical drain cleaners or calling a plumber.
Ensure trees are not planted too close to pipes and drainage. Trees can crack pipes and plants can bridge your damp-proof course. Brush away any garden debris before leaves and twigs block your drains.
Monitor your water pressure. Test your water pressure by monitoring how forcefully the water leaves the taps in the bath. If it is slow, your water pressure may be low. Another way is to test it with a pressure gauge or ask your water supplier or plumber to do it.
Install water alarms – they alert you before damage happens. There are various types on the market, such as LeakBot, that clip on or are attached to your water pipes