Why Does My Roof Leak Only in Heavy Rain?

Updated 2026-10-24 · Sources checked

"I have a leak under here after heavy rain. Is there anything i can do or need a roofer?"

A homeowner who started a thread on r/HomeMaintenance asked exactly that.

Heavy or wind-driven rain can push water in at spots that stay dry otherwise: roof vents¹, the flashing around pipes and vents² and the edge where the roof meets a wall³. Leaks are rarely directly above the ceiling stain⁴, so the stain won't show you the entry point. You can do a lot from inside today. A roofer is the one to find and fix the entry.

Quick answer:

Write down where the water shows, when it starts and which way the wind blows.
Catch the drips, move belongings away and photograph the damage with the date before any cleanup⁵.
Look with binoculars from the ground and for a drip trail in the attic, never from the roof⁴.
Ask a roofer to show you where the water enters before you pay for a repair, since a professional roofing contractor should do the closer assessment and the repair⁶.

On this page

Why does my roof leak only in heavy rain?
The order that works
If the roofer can't come today
How do I check where it leaks without climbing up?
Why a patch may not hold, and what to get in writing
Checklist before you call
Quick questions

The notes, the buckets and the photos are all in your hands today; the roof itself can wait for a roofer.

Why does my roof leak only in heavy rain?

Because in heavy wind and sideways rain, water reaches weak spots that a gentle shower doesn't test. Roof vents are one of the most common routes for rainwater into a house¹, and wind is what makes soffit vent openings, the slots under the roof overhang, prone to letting rain in¹. Pipes, plumbing stacks, flues and vents through the roof should be sealed with boot or collar flashing², the sealing strip around them. In big storms, gutters can overflow and stream water down the walls³, which makes the roof-to-wall edge another way in.

This page is about pitched shingle roofs; flat roofs have their own weak spots. One commenter in a r/Roofing thread about a downpour drip guessed: "Probably leaking from the top side or from a driving rain at the corners." That is a fair place to start looking, not a diagnosis.

Who can trace a leak that only shows up in a storm? Who to call when a roof leaks.

The order that works

Protect and record, from inside. Put a bucket under the drip and move belongings out of the way. If a stream of water is coming in, deal with that before anything else. Take reasonable steps to protect your property from further damage⁵, and keep your notes of where, when and which wind.
Find where it comes from, without climbing. Binoculars from the ground first, then the attic, as in the checks below.
Get ready, then call a roofer you choose. Take your notes, your photos and the questions further down.
If you think you may file a claim, wait for the adjuster. Avoid throwing out damaged items until the adjuster has visited⁵. In Texas, make only temporary repairs until the insurance company sees the damage⁷. Inside, temporary means buckets and towels. Wherever you live, ask your insurer what it needs to see before repairs.

If the roofer can't come today

Keep emptying the buckets, and dry wet areas and items inside within 24-48 hours to prevent mold⁸.
If you may file a claim, save receipts for anything you buy to protect the house; you may be able to submit them to your insurance company later⁵.
After the next hard rain, look again with binoculars and check the attic⁴, and add what you see to your notes.

How do I check where it leaks without climbing up?

Stay on the ground and in the attic: don't risk serious injury trying to inspect or repair the roof⁴. Here is what to look for.

From the ground, with binoculars: pipes, stacks or vents with no boot or collar flashing² around them, and gutters that overflow down the wall in a storm.
In the attic: water staining and damp wood⁹, and a drip trail⁴.

What you find tells the roofer where to start:

Staining or damp wood by a pipe or vent: tell the roofer to check that pipe's flashing².
Water down a wall where the roof meets it, or an overflowing gutter: ask about the roof-to-wall edge³.
Water showing at a vent in wind-driven rain: point to the vent itself¹.
A ceiling stain with nothing above it in the attic: say that the stain is rarely the entry point⁴, and ask the roofer to trace the water back.

Does the water show up where two roof slopes meet? What to check on a roof valley leak.

Why a patch may not hold, and what to get in writing

A patch put over the stain can miss the real entry, and then the next heavy rain brings the leak back. One commenter in a thread about a roof replaced five months earlier wrote: "they replaced my old flashing, thought that would fix the issues, still leaking now due to the heavy rain today"

Before you pay, ask the roofer to show you the entry point with photos, and to put in writing what happens if it leaks again. You can send this:

Please show me with photos where the water is getting in, and write in the estimate what you will do if it leaks again after the next heavy rain. Please also list each repair separately.

If a roofer pushes you to sign before explaining where the water gets in, that is an answer too: weigh it against the bids that do.

Curious how far a tube of sealant gets you with a leak? What roof sealant can and can't fix.

Checklist before you call

Your notes: where the water shows, when it starts, which way the wind blows.
Your photos, taken before cleanup.
What you saw from the ground and in the attic.
The two questions above, written down.
Receipts for anything you bought to protect the house.

Leak Log: when and where the water shows up

Note each time water has shown up inside: the date, the weather and where. You'll get a dated log to print, what to keep with it, and a message for a roofer you choose. Nothing you enter is saved or sent, so print or copy it before you leave the page. The printout has blank rows to add the next time by hand.

Your browser isn't running scripts, so here is the general version: what to note each time water shows up, and what to keep with your notes.What to note each time water shows up

The date and the weather, each time. In Texas, for example, the advice when a house is damaged is to write down the time and date you first saw the damage, and to note what the weather was like at the time.¹²

When it started and the wind: soon after the rain began, after a long or hard rain, or after the rain stopped; and which way the wind blew.

Where it showed: which room's ceiling or wall, the attic, or around a chimney, skylight, vent or pipe, or a light fixture or fan.

What you saw: dripping, a wet spot or stain, a stain that grew, water running down, or damp insulation or wood.

What to keep with your notes

Photos or video before any repairs. Texas also advises taking pictures or videos of the damage before making any repairs, if possible.⁷

Receipts. Save receipts for what you spend.⁵

If water shows up when it isn't raining

It is quite common to find houses in which kitchen ranges, bathroom exhaust fans, and dryers vent their moist air into the attic rather than outside.¹¹

If the water is at a light fixture or fan

Turn off electricity before assessing damage, to avoid accident or injury.¹⁰

Your notes, by hand

Next time · Date: ____________ · Weather: ____________ · Where: ________________ · What you saw: ________________

Share your notes with a roofer you choose.

Quick questions

What roof sealant can I use in the rain?

Leave the sealant alone for now. Trying to repair a roof yourself risks serious injury⁴, so use buckets and towels inside and let the roofer choose the repair once the entry point is clear.

Is it normal for a roof to leak only in heavy rain?

A roof that leaks every time there is heavy rain is not something to wait out. The notes you take now (where, when, which wind) are what let someone find it later.

Does a ridge vent leak in heavy rain?

It can; a vent is one way in. Upper roof vents should be selected and installed to resist wind-blown rain¹, so if water shows near one, ask whether that vent was built and installed to do that.

How can a roofer find a leak that isn't there on a dry day?

Your notes and photos tell the roofer where to start, and the attic can show water staining and damp wood⁹ even when it isn't raining. Ask whether they will follow the drip trail in the attic⁴ back from the stain, since the entry is rarely right above the stain⁴. Also ask what they will do if they cannot find the entry on a dry day, and to show you the spot.