Roof leak after rain: how to find and stop it
Quick answer
A leak that shows up only during or after rain is almost always getting in through the roof or its flashings, then traveling along rafters before it drips — so the wet spot inside is often not directly below the entry point. Contain the water first, then trace upslope from the interior stain toward the roof to find where it's actually entering.
Common causes
- Cracked, curled, or missing shingles, especially on older roofs.
- Failed flashing around chimneys, skylights, vents, and where the roof meets a wall — the #1 source of mystery leaks.
- Clogged gutters and valleys backing water up under the shingles.
- Ice dams in cold climates forcing meltwater under the roof edge.
- Worn or cracked rubber boots around plumbing vent pipes.
What to check first
- From inside the attic during or right after rain, follow water tracks upslope on the rafters and decking to the entry point.
- Inspect flashing and vent boots — these fail long before the field of the roof does.
- Check gutters and valleys for clogs and standing water.
- From the ground with binoculars, scan for missing, lifted, or granule-bald shingles (don't climb a wet roof).
When it's urgent
Active dripping near electrical, a sagging ceiling, or water pouring in during a storm is urgent — contain it (bucket, tarp the affected area from inside, cut power to wet fixtures) and get a roofer out quickly. Don't go on a wet or steep roof yourself; falls are the real danger here.
DIY vs. call a pro
You can likely DIY
- Containing the leak and protecting belongings.
- Clearing gutters and valleys.
- Replacing a single accessible vent boot or a few shingles if you're comfortable and the roof is low-slope and dry.
Call a pro for
- Flashing repairs and anything near a chimney, skylight, or roof-to-wall junction.
- Steep or high roofs, or any repair requiring walking the roof.
- Recurring leaks, widespread shingle failure, or signs the roof is near end of life.
Estimated cost range
How HouseCue helps
HouseCue is a private, homeowner-first app that turns this from a one-time worry into a tracked plan. Snap a photo for an AI diagnosis, upload your inspection report to auto-build a handbook, and get seasonal reminders for your roof, HVAC, water heater, plumbing, and electrical — so nothing slips. Connecting with a pro is always optional and only when you choose.
Get started freeFrequently asked questions
Why does my roof only leak sometimes when it rains?
Wind-driven rain, the rain's duration, and the angle all matter. A small flashing gap may only let water in during a long soaking rain or a storm from a particular direction, which is why intermittent leaks are so hard to trace.
Can I find a roof leak from inside?
Often yes — the attic is the best place to start. Water tends to enter high and run down the rafters before dripping, so trace the wet tracks upslope to find the real entry point, which is usually above and uphill of the interior stain.
Should I get on the roof to fix a leak myself?
Be very cautious. Falls are the biggest risk, and wet or steep roofs are dangerous. Ground-level inspection and attic tracing are safe; actual roof work — especially flashing — is usually best left to a roofer.
Related guides
HouseCue guides are general educational information, not professional inspection, engineering, or contracting advice. Costs vary by market. For safety issues — gas, electrical, structural, or major water — contact a qualified professional.