Roof Leak: Find the Source, Stop Ice Dams and Limit Water Damage

A roof leak is usually caused by damaged or aging roof covering, failed flashing around vents, chimneys and skylights, clogged gutters, or ice dams in winter. When your roof is leaking, catch the water inside, shut off power to any wet light fixtures, photograph the damage, and arrange a temporary cover or repair once it is safe; the Insurance Institute for Business & Home Safety (IBHS) names roof penetrations, flashing and degraded roof covers among the most common sources of interior water damage.

What to do when your roof is leaking

1. Stay off the roof during rain, wind, snow or ice. The University of Minnesota Extension warns that anyone on the roof in winter, or working on it from below, risks injury.
2. Make it electrically safe. If water is coming through a light fixture, ceiling fan or near outlets, turn off that circuit at the breaker. The CDC says never to touch switches or electrical equipment while standing in water, and to call an electrician if you cannot reach the panel safely.
3. Catch the water. Put buckets or bins under drips, and lay towels or plastic sheeting to protect floors.
4. Move belongings out of the wet area, especially electronics, furniture and papers.
5. Watch the ceiling. A bulging or sagging ceiling is holding water and can give way. Keep people and pets out from underneath it.
6. Check the attic with a flashlight if you can do so safely. You may be able to see where water is entering and place a container there.
7. Document the damage with photos and video, inside and outside, before cleanup. The Insurance Information Institute advises documenting damage and keeping receipts for temporary repairs.
8. Arrange a temporary fix. A roofer can tarp or patch the roof once conditions are safe. Then plan the permanent repair and dry the inside.

How to find a roof leak

Water rarely drips straight down from the hole. It often runs along roof decking, rafters or the top of insulation before it shows up on the ceiling, so the stain may be some distance from the actual entry point.

1. Start in the attic. During or right after rain, look for wet decking, water trails on rafters, damp or matted insulation, and daylight through the roof boards.
2. Trace uphill. Follow stains or water trails up the slope to the highest wet point. That is closer to the source.
3. Check penetrations first. IBHS's winter checklist tells homeowners to check and repair gaps or broken seals around vent stacks, chimneys and corners. The IBHS interior water report also lists flashing around roof penetrations, valleys, drip edge and vents as common problem areas.
4. Look from the ground with binoculars for missing, curled or cracked shingles, lifted flashing, and debris in valleys.
5. Try a hose test in dry weather with a helper. One person runs a hose on one small section of roof at a time, starting low and working up, while the other watches inside for drips. This is slow and should only be done if you can work safely on a ladder or the roof is low-slope and dry. Many homeowners leave it to a roofer.

Common roof leak sources

Ice dams: how they cause roof leaks

An ice dam is a ridge of ice that forms at the edge of a roof and traps melting snow behind it. The University of Minnesota Extension explains that ice dams need snow on the roof and uneven roof temperatures: higher parts of the roof are above 32 degrees F while the lower edge stays below freezing. Snow melts on the warm upper roof, runs down, and refreezes at the cold eaves. IBHS adds that the trapped water can be pushed under shingles and into the attic or walls.

IBHS says ice dams most commonly form on older homes with inadequate attic insulation, and that newer homes built under modern codes have nearly eliminated the hazard.

What to do about an ice dam now

• Remove snow from the ground. IBHS recommends a roof rake, ideally with wheels so the blade stays above the roof covering. UMN Extension notes raking can damage roofing materials, so work gently.
• Make a drainage channel in an emergency. UMN Extension says that if water is leaking inside, hosing a channel through the dam with tap water on a warm day, working upward from the lower edge, can let water drain. It calls this a temporary solution.
• Do not chip at the ice with hammers or axes, and never use a torch or open flame on a roof.
• Avoid power lines. IBHS warns to use extreme caution with your footing and to stay away from where power lines enter the home.
• Consider hiring help. IBHS suggests an established, licensed, insured professional for roof snow removal.

Preventing ice dams long term

UMN Extension says the first step is making the ceiling airtight so warm, moist air cannot flow from the house into the attic, then considering more ceiling or roof insulation. IBHS also lists improved attic ventilation, more insulation and sealed ceiling openings. UMN Extension does not recommend mechanical attic ventilation for ice dams in Minnesota because it can cause other moisture problems. Heating cables on eaves and gutters will not remove an existing dam, IBHS notes, but professionally installed, listed cables can create channels for water to drain.

Roof leak damage inside the home

A small roof leak can spread further than it looks:

• Ceilings and drywall absorb water, stain and can sag. See our ceiling water damage page and our water stains on ceiling guide.
• Insulation compresses and stays wet, which reduces its value and holds moisture against framing.
• Attic framing and decking can stay damp for long periods.
• Mold can follow. The EPA says wet materials dried within 24 to 48 hours usually will not grow mold. Roof mold removal and attic mold are covered in our attic and crawl space mold guide.

UMN Extension advises not repairing interior damage until ceilings and walls are dry, and fixing the cause at the same time, or the damage is likely to return. Our drying out water damage guide explains how to confirm materials are dry.

How do you know if a ceiling leak is serious?

Treat it as serious if the ceiling is sagging or bulging, water is coming through a light fixture, the stain is growing quickly, the drywall feels soft, or more than one spot is leaking. Those signs call for shutting off power to the area and getting help quickly. A small, dry stain that does not change after rain is less urgent, but still worth tracing to its source. Our signs of water damage guide lists other clues.

Roof leak fix cost: what drives the price

There is no reliable single price for a roof leak repair. Cost depends on:

• The source: resealing a vent boot or replacing a few shingles is a smaller job than reflashing a chimney or skylight.
• Roof material: asphalt shingle, tile, metal and flat roofs each need different materials and skills. A roof tile leak may require matching tiles.
• Pitch, height and access: steep or tall roofs need more safety equipment and time.
• Roof age and condition: an old roof may need sections replaced rather than patched.
• Hidden damage: rotted decking found once shingles come off adds cost.
• Interior repairs: drying, drywall, insulation, paint and any mold work are separate from the roof itself.
• Emergency timing: tarping during a storm adds a separate visit.

Roof leak tar and sealant products can patch a small leak temporarily, but they are a stopgap, not a repair.

Does homeowners insurance cover roof leaks?

It depends on the cause. The Insurance Information Institute says standard homeowners policies cover damage resulting from ice dams and wind-driven rain, and that water coming from the top down, such as rainfall, is generally covered. It also says policies will not cover damage due to lack of maintenance, so a leak from an old, neglected roof may be denied. Report damage promptly, photograph it, and keep receipts. Our water damage insurance claims guide walks through the process.

Renters: if you have an apartment roof leaking, tell your landlord or property manager in writing right away, with photos. Repairs to the building are usually the owner's responsibility; your own renters policy is generally about your belongings, so check it.

Prevent future roof leaks

• Inspect before winter and after major storms. IBHS recommends a roof inspection ahead of winter weather focused on aging or damaged roofing, loose shingles and seals around vents and chimneys.
• Clean gutters and downspouts, and route downspouts at least 3 to 4 feet from the foundation, as IBHS advises.
• Trim overhanging branches. IBHS notes branches against or over the house can damage the roof.
• Air seal and insulate the attic to reduce ice dam risk.

When storm water has already reached ceilings, walls or insulation, professional storm damage restoration can handle drying and cleanup while a roofer fixes the source. You can browse help by area on our locations page, and our storm damage restoration page explains what that work usually covers.

Flood Rescue Pros is a free service that connects homeowners with independent local water damage restoration companies. If you would like to be connected with one near you, Get help now.

Frequently asked questions

What should I do first when my roof is leaking?

Catch the water, turn off power to any wet fixtures, move belongings, and take photos. Stay off the roof in bad weather and arrange a temporary tarp or repair once it is safe.

How do I find where my roof is leaking from?

Start in the attic during or after rain and follow water trails uphill to the highest wet point. Check vents, chimneys, skylights and valleys first, since water often travels before it drips.

How much will it cost to repair a leaking roof?

It depends on the source, roof material, pitch, roof age, hidden decking damage and interior repairs. Get a written estimate that separates the roof repair from interior damage.

Does homeowners insurance cover roof leaks?

Sudden damage, such as from wind-driven rain or ice dams, is generally covered, according to the Insurance Information Institute. Damage caused by lack of maintenance is not covered, so a leak from a neglected, worn-out roof may be denied.

Can I stop a roof leak from inside?

You can catch and contain water from inside, and in the attic you may be able to direct drips into a container. A real fix has to be made on the roof surface where the water enters.

Key facts

• Common roof leak sources are damaged or aging roof covering, flashing at vents, chimneys and skylights, valleys, gutters and ice dams (IBHS).
• Water travels along decking and rafters, so trace stains uphill from the attic to find the source.
• Ice dams form when upper roof areas are above 32°F while eaves stay below freezing (University of Minnesota Extension).
• Never chip ice dams or use open flame; use a roof rake from the ground or hire a professional.
• Standard policies generally cover sudden roof water damage and ice dams, but not damage from lack of maintenance (Insurance Information Institute).
• Dry wet ceilings and insulation within 24 to 48 hours to lower mold risk (EPA), and repair interiors only after they are dry.