Checking Your Chimney After a Storm

Chimney Academy · Safety · Updated October 2026

The first hour: what comes before the chimney

Start with what can hurt you today. If a limb or tree has come down on the house or near the service wire, keep everyone away from it and call the utility or emergency services. Treat any wire on the ground as live.

Next, think about the heating appliances. If the power went out and you plan to use a fireplace or wood stove for warmth, pause before lighting anything. A storm that took shingles off a roof may also have knocked a cap sideways, packed leaves into a flue or loosened a section of pipe. A fire lit into a damaged or blocked chimney can push smoke and carbon monoxide into the living space.

If you are running a portable generator, keep it outdoors and well away from windows, and make sure a battery-powered carbon monoxide alarm is working. The CDC specifically recommends a battery-powered or battery backup detector when a generator is in use.

Only after the house itself is safe does it make sense to walk around and look at the chimney. Do it in daylight, once the wind has dropped and the surfaces are no longer slick.

What different storms tend to do to a chimney

Each kind of weather leaves a different signature, which is useful because it tells you where to look.

High wind

Wind pushes on everything that sticks up from the roof. A chimney cap, a chase cover or a section of metal pipe may be bent, lifted or blown off entirely. Wind also drives rain sideways, so water can reach joints that stay dry in ordinary weather.

Falling limbs and flying debris

A branch does not need to hit the chimney to cause trouble. It can scrape the flashing, tear a shingle at the base or knock a cap out of square.

Hail

Hail dents thin metal such as caps and chase covers, and it can chip or crack the surface of a mortar crown. Small hits on a crown may not matter right away, but they give water a way in, and water is the long-term enemy of masonry. A Fire Engineering article summarizing industry guidance puts it bluntly: water causes more damage to masonry chimneys than fire does.

Lightning

A strike near or on a chimney can crack masonry or dislodge pieces, and it may leave scorch marks or debris scattered on the roof or ground. Lightning can also affect wiring and gas controls inside the house, which is a separate matter for an electrician or the gas utility.

A ground-level checklist you can do safely

You do not need a ladder, and you should not use one. Binoculars and a phone camera with zoom do most of the work. Walk the full perimeter, because a chimney looks different from each side.

1. Look at the silhouette. Does the top of the chimney look the same as it did last week? A leaning line, a missing cap or a ragged top edge stands out when you compare against an older photo.
2. Scan the ground below. Chunks of brick, mortar, flue tile, bent metal or pieces of a cap that landed in the yard or on a lower roof point to something that came loose from above.
3. Check the cap or cover. Is it present, level and attached? Is there a visible gap between it and the chimney?
4. Look at the crown. The crown is the sloped slab across the top of the masonry. Binoculars may show new cracks, missing chunks or a flat spot where water could sit.
5. Follow the mortar joints. Fresh gaps, dark open lines or bricks that appear to have shifted are worth noting.
6. Check where the chimney meets the roof. Bent or lifted metal flashing, torn shingles or exposed roofing material around the base can let water run behind the chimney.
7. Look at the lean and gap. A new space between the chimney and the siding or wall is a reason to stay cautious and call someone. Our guide to a leaning chimney or a gap between chimney and house explains why.

What to check inside the house

Water and debris often announce themselves indoors before anything is obvious outside, so a quick tour is worthwhile.

• Ceilings and walls near the chimney, including the attic side if you can see it from the hatch without stepping on anything unsafe. Look for new damp patches, bubbling paint or a musty smell.
• The firebox or stove. With the appliance cold, look for loose debris, bits of mortar or tile, or water on the hearth. Wet soot and a sharp smell after rain can mean water is getting down the flue.
• Alarms. Press the test button on carbon monoxide and smoke alarms, especially if the power flickered or you are about to rely on a fire for heat.

The NPS preservation brief on moisture recommends tracing water from the outside in and from the top down, because water often travels well away from where it entered. A stain on a ceiling may be several feet from the real opening. Our guide on stains on walls and ceilings near the chimney covers that detective work.

What to photograph and write down

Documentation costs nothing and helps with every conversation that follows, whether that is with a chimney professional, a roofer or an insurance company. Check your own policy for what it expects.

• A wide shot of each side of the chimney from the ground, so the overall condition is clear.
• Close shots, using zoom rather than getting nearer, of any cracked, missing or displaced parts.
• Debris on the ground, with something in the frame for scale, such as a shoe.
• Interior stains or damp areas, with a note of the date and whether it was still raining.
• A short written note: date, type of storm, what you noticed first, and anything you did.

Take new photos after the next rain to see whether a problem is growing.

Reading what you found

This table matches common observations to what they may mean. It is a guide to the questions worth asking, not a diagnosis. Only an inspection confirms the actual condition.

When to call a professional, and what this guide cannot tell you

Call for an inspection when you see any damage listed above, when debris from the chimney is on the ground, when water appears inside near the chimney, or when you simply cannot tell. A chimney inspection looks at the interior of the flue as well as the exterior, which is where storm damage is easiest to miss. CSIA notes that an annual inspection is recommended for chimneys, including ones that are rarely used, because nests, debris and deterioration can make them unsafe.

What this guide cannot do: it cannot tell you whether the inside of your flue is intact, whether the structure is sound, or how urgent a specific crack is. It also does not replace the advice of your local fire official or building department if the damage is significant. If you see structural movement, active water entry or any sign of fire, treat it as urgent and call emergency services where appropriate.

When a professional visits, ask them to explain what they find and the options before any work begins. Photos from your own walk-around make that conversation faster and more precise.

Frequently asked questions

Related reading

• Why is my chimney leaking?
• Signs to stop using your fireplace
• Chimney inspection
• Chimney camera inspection