Why does my ceiling leak only when it rains?

If you are on the top floor, rain-linked leaks usually mean the roof or flashing, not plumbing. If it leaks regardless of weather, it is more likely a pipe, tank or bathroom above.

Common plumbing problems

Water leaking from the ceiling: what to do now

Guidance built with working UK plumbers · Last updated July 2026

Water coming through a ceiling almost always comes from directly above — a leaking supply or waste pipe, an overflowing cistern or cold-water tank, a failed shower tray or seal, or, after a cold snap, a burst pipe. Treat a bulging or sagging ceiling as urgent: it can hold a surprising amount of water and give way.

Amber to red depending on what you see. A faint stain is amber. A ceiling that's bulging, sagging or dripping fast is red — turn off the water at the stopcock, keep people clear, and mind the electrics.

Do this now

Stop the water. Turn off the mains at the stopcock to cut supply to whatever's leaking above.
Electrical safety. If water is near a light fitting or spreading, switch that circuit off at the consumer unit. Never touch a wet light fitting — water and electrics together are dangerous. Unsure? Call an electrician.
Contain it. Bucket under the drip, move furniture, lift rugs and electricals clear.
Find what's above. A bathroom, the cold tank in the loft, or a pipe run — this tells you (and any plumber) where to look.
Bulging ceiling holding water? It can collapse. Stay out from under it. Controlled piercing to drain it is sometimes done, but it's a judgement call — if you're unsure, get a professional.

Likely causes

Clue	Likely cause
Below a bathroom, worse after showers	Shower tray/seal or waste leak
Steady, unrelated to use	Leaking supply pipe or overflowing tank
Sudden, after cold weather	Burst pipe
Top floor, worse when raining	Roof or flashing, not plumbing

When to call a professional

Call for help if the ceiling is bulging or sagging, if electrics are wet (electrician), if you can't find or stop the source, or if you're on the top floor and it may be the roof. LeakScan gives guidance — it's not a substitute for a qualified plumber, electrician or roofer.

Questions, answered straight

Is a ceiling leak an emergency?

A slow stain is amber; a bulging, sagging or fast-dripping ceiling is red — it can collapse. Stop the water and keep clear.

Should I turn off the electrics?

Yes if water is near a light fitting or spreading — switch that circuit off at the consumer unit and don't touch wet fittings.

Why does it only leak when it rains?

On a top floor, rain-linked leaks usually mean the roof or flashing rather than plumbing.

Will the ceiling collapse?

A ceiling visibly holding water can collapse. Stay out from under it and get it drained safely by a pro.

Not sure where it's coming from?

Snap a photo and LeakScan names the likely cause, rates how urgent it is, and tells you what to do next.

Get early access →

Snap it. Know it. Fix it.

Or enter this week’s free plumber draw →

Renting? LeakScan sends the photo, the AI diagnosis and how urgent it is straight to your landlord’s inbox — timestamped proof you reported it. A landlord? Every tenant report lands in one place. See how →