Leaking Roof? Signs to Look For and What to Do Straight Away

A leaking roof is one of the most common problems homeowners face in the wet autumn and winter months. Even a small leak can do serious damage if it's left, soaking insulation, staining ceilings, rotting timbers and, in the worst cases, bringing a ceiling down.

Here's how to spot a leak early, what to do straight away, and when it's time to call in a roofer.

Warning Signs of a Leaking Roof

Some leaks are obvious, but many start quietly. Look out for:

• Water stains on ceilings — yellow or brown rings, often in upstairs rooms or near chimney breasts
• Drips or water running down walls during or after heavy rain
• Damp patches that grow after rain and shrink in dry spells
• Bubbling or sagging ceiling plaster
• Mould or a musty smell in upstairs rooms or the loft
• Wet or compressed loft insulation
• Daylight showing through the roof boards or tiles when you look from the loft
• Damp or dark roof timbers in the loft
• Slipped, cracked or missing tiles or slates visible from the ground
• Granules from felt or tiles collecting in gutters

What to Do Straight Away

If you've found a leak, these steps will help limit the damage until a roofer can get to you:

1. Catch the water. Put buckets, bowls or towels under drips and move furniture, rugs and electronics out of the way.
2. Check the loft. If it's safe, go up with a torch and look for where the water is coming in. Put a bucket or a sheet of plastic down to protect the insulation and ceiling below.
3. Watch out for a bulging ceiling. If plaster is sagging with trapped water, keep everyone out of the room. A small, controlled puncture in the lowest point over a bucket can relieve the pressure, but if you're unsure, leave it to a professional.
4. Turn off electrics if water is near lights or sockets. Switch off the affected circuit at the consumer unit and don't touch wet fittings.
5. Take photos. Record the damage inside and out for your records and any insurance claim.
6. Call a roofer. Many offer emergency call-outs and can put a temporary cover on until a full repair is possible.

Safety first: never climb onto a roof yourself, especially in wet, icy or windy weather. Roof work is dangerous and best left to professionals with the right equipment.

Common Causes of Roof Leaks

Slipped, Cracked or Missing Tiles and Slates

High winds and storms can dislodge tiles and slates, leaving gaps for rain to get through. This is one of the most common causes of leaks after bad weather.

Damaged Flashing

Flashing is the lead or metal strip that seals the joins around chimneys, skylights, dormers and walls. If it cracks, lifts or the mortar holding it fails, water can run straight in.

Chimney Problems

Cracked flaunching (the mortar around the chimney pots), crumbling pointing or a missing cap can let water into the chimney stack and down into the rooms below.

Blocked Gutters and Valleys

Leaves and debris can block gutters and roof valleys, causing water to back up under tiles or overflow down walls. This often shows up as damp near the top of walls or around the eaves.

Worn Roofing Felt or Underlay

On older roofs, the felt under the tiles can perish, tear or sag. When that happens, any water blown under the tiles has nowhere to go but into the loft.

Flat Roof Failures

Flat roofs on extensions, garages and dormers are prone to cracks, blisters and pooling water, especially as they age. Felt flat roofs typically need attention sooner than modern EPDM rubber or GRP fibreglass roofs.

Ridge and Verge Problems

Cracked or loose mortar on ridge tiles and verges can let water in along the top and edges of the roof, and may cause tiles to come loose in high winds.

Condensation in the Loft

Not every wet loft is a leak. Poor loft ventilation can cause condensation to form on the underside of the roof and drip onto insulation, especially in cold weather. A roofer can tell you which one you're dealing with.

Repair or Replace?

Most leaks can be fixed with a targeted repair, such as replacing a few tiles, renewing flashing or repointing a chimney. However, a full or partial re-roof may be worth considering if:

• The roof is near the end of its life and leaks keep coming back in different places
• The felt underlay has failed across large areas
• Lots of tiles or slates are cracked, porous or sliding
• Roof timbers are rotten or sagging

A good roofer will inspect the roof properly and explain your options honestly, rather than pushing a full replacement when a repair will do.

How to Help Prevent Roof Leaks

• Get your roof checked once a year, ideally in autumn before the worst weather
• Clear gutters, downpipes and valleys of leaves and debris
• Check from the ground after storms for slipped or missing tiles
• Look in the loft every few months for stains, damp or daylight
• Make sure the loft is properly ventilated
• Get small problems fixed quickly before they turn into big ones

Don't Wait for It to Get Worse

Roof leaks rarely stop on their own, and the longer water gets in, the more expensive the repair becomes. A quick fix to a few tiles or a strip of flashing now can save you from replacing insulation, ceilings and roof timbers later.

Got a leaking roof? Post your job for free on Compare My Builder and get quotes from verified local roofers. Compare profiles, reviews and prices, and get your roof sorted before the next downpour.