Most leaks have one clear cause: a gap has opened somewhere above, and water has found it. The tricky part is that the drip inside is rarely above the actual gap. Water runs down the felt or a rafter first, so the real hole can be some distance away. This guide shows you how to trace it, what usually causes it, and when to call someone out.
First steps when your roof is leaking
Limit the damage before anything else. Move valuables out from under the wet patch and put a bucket down. If a ceiling bulges with trapped water, pierce it carefully from below with a screwdriver, over a bucket. A controlled release is far better than a surprise collapse.
Photograph everything: the stain, any damage outside, and the date. If a storm caused it, this is exactly what an insurer will ask for later, and our storm damage claims guide walks through that process in full.
One thing you should not do is climb onto the roof yourself. Wet tiles and slates are dangerously slippery, and a fall is a far worse outcome than waiting a day for a professional.
How to find where a roof is leaking
The entry point is almost always higher up the slope than the stain inside. Water tracks along the underlay first, then drips off at a low point. A roofer tracing a leak checks these spots, roughly in this order.
- flashing around any chimney or wall junction
- valleys, where two roof slopes meet
- ridge and hip tiles, for cracked mortar
- individual slipped or cracked tiles
- flat sections, for splits, blistering or ponding water
A torch check in the loft after rain often shows a damp trail. It usually leads back to the entry point. Pass this on when you book a repair, since it saves the roofer time.
Common causes of a leaking roof
A large share of “roof leaks” are actually chimney lead failures rather than a problem with the tiles themselves. Lead flashing lifts, cracks, or gets badly patched with cement — a common short-term fix that fails within a season. Water then tracks down behind the stack and shows up well away from the chimney. Our lead flashing failure signs guide covers what to look for.
Valleys, where two slopes meet, carry more water than any other part of a roof. A cracked valley tile or a build-up of debris there causes some of the worst leaks, because water backs up instead of simply dripping through.
Flat roof sections fail differently: ponding water eventually finds a pinhole, or the felt blisters and splits. A flat roof that has held for years can start leaking fast once the covering reaches the end of its life.
Blocked gutters cause more leaks than most homeowners expect. Once a gutter overflows, water runs back under the eaves instead of away from the house. It can soak into the roof timbers from below rather than above. See our blocked gutters guide, and our gutter repair vs replacement guide if yours needs fixing, not just clearing.
The most straightforward cause, and the easiest to fix, is a slipped or cracked tile after a storm — provided it is caught before the felt underneath perishes too. Our roof underlay guide explains what that layer actually does, since it is the last line of defence once a tile fails.
Temporary fixes vs a proper repair
A tarpaulin or a smear of sealant can buy you time, but it is a stopgap, not a repair. The right fix depends entirely on the cause. A slipped tile gets refitted, failed lead gets re-dressed, and a cracked valley gets replaced rather than sealed over. Be wary of anyone who offers a quick “seal it and it’ll be fine” fix without explaining what failed. That is how the same leak comes back a year later, usually worse.
What roof leak repairs cost
Costs vary widely with the cause. A handful of slipped tiles is a different job to a lead valley that needs stripping and relaying. See our roofing costs guide for realistic UK price ranges across repair types, since access and materials matter as much as the size of the leak.
Insurance, inspections, and calling a roofer
Storm-related leaks are usually covered by home insurance, while wear-and-tear leaks generally are not. Our home insurance and roof repair guide sets out what most policies expect from a claim. Many leaks trace back to a fault a routine check would have caught, so read our how often to inspect a roof guide before the next one starts.
Treat active water, tiles hanging above a path, or a storm-stripped section as an emergency. Do not wait for a routine slot. Our emergency roof repair guide, part of our wider emergency roofing coverage, sets out exactly what to do while you wait.
Find Trusted Roofers connects UK homeowners with local roofers who trace a leak properly instead of just patching the symptom. That includes emergency roofers in Liverpool and roofers in Edinburgh and Swindon, plus roofers who cover Norwich. Tell us about the problem and we’ll match you with someone who covers your postcode.
Leaking Roof? Causes, Fixes & What To Do — FAQs
Why has my roof started leaking suddenly?
Sudden leaks usually follow a specific event. A storm may loosen tiles or flashing, a blocked gutter may overflow into the eaves, or ice and snow may force water under tiles. If nothing obvious changed, a slow leak that finally soaked through is more likely, since the damage may have started weeks earlier.
Can I fix a roof leak myself?
You can limit the damage inside with buckets, moving belongings, or piercing a bulging ceiling bubble over a bucket. Going onto the roof yourself is not worth the risk, though, and a temporary patch from the ground rarely fixes the actual cause. Get it inspected properly.
How much does it cost to fix a leaking roof?
A straightforward repair, such as a slipped tile or a small flashing fix, is often £150–£400. Valley leaks, chimney lead failures or damage that's spread into the timbers cost more, since the roofer has to open the roof up to fix them. See our roofing costs guide for fuller ranges.
Will a leaking roof be covered by insurance?
Storm damage is usually covered, while a leak from wear and tear or poor maintenance generally isn't. Photograph the damage and get a written report from the roofer stating the likely cause, since that's what insurers ask for.
How urgent is a roof leak?
Active water ingress is always urgent, since even a slow drip left for weeks can rot timbers and ruin ceilings. Treat any leak as something to get looked at within a few days, and anything with water actively coming through as same-week or emergency.
