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Why Is My Roof Leaking Near the Chimney Flashing?

Last updated October 25, 2026

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The short answer

What Is Chimney Flashing

Chimney flashing is the protective layer of metal, usually aluminum or copper, or rubberized material that covers the gap where the chimney meets your roof. It redirects rainwater away from the seam, keeping the roof deck and the interior of your home dry. Without proper flashing, water finds the smallest path through the joint.

Flashing has two main parts: the base flashing, which lies flat on the roof, and the counter-flashing, which is embedded into the chimney mortar. Both need to be secure and sealed. Over time, the sealant between them can dry out, crack, or shrink, especially after many freeze-thaw cycles in a humid continental climate.

Common Causes of Leaks

A common cause is age. The flashing material can corrode, especially in areas with heavy snow and ice melt chemicals. Another frequent issue is improper installation. If the flashing was not installed with the correct overlap or slope, water can pool and eventually work its way under the edges.

Physical damage also happens. A falling branch, ice dam, or even a repair person walking on the roof can dent or shift the flashing. Sometimes the chimney itself settles or the mortar cracks, breaking the seal with the counter-flashing. Each of these creates an opening for water to enter.

Look for visible signs like rust, gaps, or lifted edges. Also check the attic for water stains, damp insulation, or daylight showing through the roof. If you see any, the flashing is likely compromised.

  • Cracked or dried sealant at the joints
  • Rusted or corroded metal flashing
  • Flashing that has pulled away from the chimney
  • Missing counter-flashing or step flashing
  • Ice dams pushing water up under the shingles

How Water Travels Inside

When the flashing fails, water does not necessarily drip straight down. It can run along the roof deck, soak into the underlayment, and then travel down the rafters or through the ceiling. In a brick chimney, water can absorb into the masonry and wick into the wall, showing up as a stain far from the leak source.

That is why you might see water marks on the ceiling below the chimney but not directly under the roof leak. The water follows the path of least resistance, often along the top of the drywall or along a joist. This makes the leak harder to pinpoint without a careful inspection.

Why You Should Act Fast

A small leak can become a big problem quickly. Once water gets into the roof structure, it can rot the wood, rust the nails, and create the perfect environment for mold. In a humid climate, mold can spread within days, affecting your indoor air quality and your family's health.

Also, the longer you wait, the more expensive the repair becomes. A simple flashing fix might be all you need now, but if you delay, you could end up replacing roof sheathing, insulation, and drywall. Acting quickly also helps you avoid the risk of electrical hazards if water reaches wiring.

See a doctor if you feel unwell from mold exposure, and check your policy to understand what your insurance company might cover. Policies vary, and your insurer decides what is covered.

What to Do Next

First, try to stop the active leak temporarily. Place a bucket under the drip and clear any debris from the roof valleys. Avoid going on the roof yourself if it is wet or icy. If you can safely reach the flashing, you might apply a temporary sealant, but that is a short-term fix.

For a lasting repair, you need a professional who can remove the old flashing, inspect the roof deck for damage, and install new flashing correctly. A roofer or a water damage pro can handle this. They can also check for hidden moisture in the surrounding wood and drywall.

Keep the number of a trusted roofer handy for when you need it. Also, consider a water damage inspection to assess any interior damage already done.

  • Place a bucket under the drip to catch water
  • Clear leaves and debris from the roof
  • Take photos of the leak and any visible damage
  • Turn off electricity in the affected area if safe
  • Call a roofer or water damage pro for an assessment

Water damage does not wait

Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.

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Frequently asked questions

Can I fix the flashing myself?

Small sealant touch-ups are possible if you are comfortable on a ladder. But flashing installation is precise. A mistake can make the leak worse. For any significant damage, hire a pro to ensure the job is done correctly and safely.

How long does a flashing repair last?

A properly installed flashing can last decades. The lifespan depends on the material, the quality of installation, and your local weather. Regular roof inspections, especially after heavy storms, help catch problems early before they cause leaks.

Will my insurance cover this repair?

It depends on the cause. If a storm damaged the roof, coverage is more likely. Gradual wear and tear is usually not covered. Check your policy for details. Policies vary, and your insurer decides what is covered.

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