How to Fix Chimney Flashing Leak – A Comprehensive Guide

December 14, 2023
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How to Fix Chimney Flashing Leak

A leaky chimney can be a big problem for homeowners. It’s not just annoying; it can also damage your roof and the inside of your home. But don’t worry! Fixing a chimney flashing leak can be easier than you think, even if you’re not a pro at fixing things. Now, you might be wondering how to fix a chimney flashing leak. 

In simple terms, to fix a chimney flashing leak, clean the area, apply roofing sealant generously along the flashing edges, and, if necessary, replace damaged flashing for a watertight seal. Conduct a final inspection to ensure a successful and lasting repair.

This guide will help you understand step by step how to do it easily.

What is Chimney Flashing?

Flashing is like a protective barrier around your chimney and the nearby roof to stop rainwater from getting inside your house and causing leaks.

Different homes might use different materials for flashing, but it’s crucial that whatever they use is waterproof. If it’s not, rain and moisture can easily get through, causing problems in your home.

Flashing is mostly made of flexible fibers, sheet metals, or plastic. They add a special material to seal the flashing and block water from getting through.

If your chimney isn’t properly sealed, it can lead to serious damage. During a rainstorm, water might start pouring into your home, causing wood to rot and attracting bugs or pests that like moisture, possibly causing infestations.

What is Chimney Flashing?

Why Chimney Flashing Can Fail

Even though chimney flashing is good at keeping water out, it can still get damaged. Some flashing materials can wear out over time, especially when exposed to the weather. Continuous exposure to the elements might make the flashing materials break down and stop working.

Types of Damage

Over time, flashing can crack or start pulling away from the chimney. When this happens, there are open spaces where water can get through because the flashing isn’t sealed correctly.

Incorrect Installation

Sometimes, even if the flashing is new, it can still leak if it’s not installed properly. If flashing is not put in the right way, it won’t create a good barrier, leaving gaps for water to get through.

Issues with Tar Sealant

In the past, people used tar to seal chimney flashing, but it’s not the best choice for chimney leak repair. Tar gets hard and cracks as it gets older, creating openings for water to enter your home.

Why Chimney Flashing Can Fail

Signs You Have a Chimney Flashing Leak

Here are signs that show you might have a leak in your chimney flashing:

1. Water stains on your ceiling or walls near the chimney.

2. Cracks or gaps around the flashing.

3. Rust on the flashing itself.

4. Debris buildup blocking the flashing channels.

5. Birds nest in the chimney (they love a cozy leak!).

How to Fix Chimney Flashing Leak

The good news is that you can usually fix most chimney flashing leaks with some effort and the right tools. Here’s a step-by-step guide:

Gather Your Supplies 

Get what you need for chimney flashing repair:

How to Fix Chimney Flashing Leak

1. Safety gear: Sturdy shoes, gloves, and goggles.

2. Cleaning tools: Broom, wire brush, and scraper.

3. Sealant: Roofing cement or caulk specifically designed for chimneys.

4. Patching materials (optional): Metal flashing sheets or pre-cut rubber boots (depending on the leak size).

5. Tools: Hammer, screwdriver, putty knife, and a caulking gun.

Prep Like a Pro

Get ready like an expert:

1. Clean up: Take away any mess around the chimney and flashing.

2. Find the leak: Follow the water stains to figure out where the problem is.

Let’s start fixing it!

1. Clean the slate: Scrub the flashing and surrounding area with the wire brush to remove dirt, rust, and loose sealant.

2. Widen the gap (optional): For minor leaks, use the scraper to widen the gap between the flashing and the chimney gently. This helps the new sealant adhere better.

3. Fill the cracks: Apply a generous amount of sealant into the gap and around the flashing edges. Use a putty knife for smooth application.

4. Patch it up (if needed): For larger holes or tears, cut a piece of flashing sheet or rubber boot to fit the size and shape of the leak. Secure it with screws or nails, then apply sealant around the edges for extra protection.

4. Let it dry: Give the sealant ample time to dry completely, usually 24 hours.

Besides, do you know how often you should sweep your chimney? Visit our insightful blog to learn all about this topic.

Bonus Tips

Below are the extra tips for results that last:

1. Check often: After storms or heavy rain, quickly look at your chimney for any issues.

2. Stop problems early: Regularly clean debris from the flashing and gutters to avoid any build-up.

3. Get help if needed: If the leak is big or you’re not comfortable with heights, it’s okay to call a professional to repair flashing around the chimney.

In addition, do you know why the chimney leaks and how to fix it? Take a look at our blog on this topic to find out the right answer.

Contact a Pro

If you need help with your chimney, go for Air Duct Now. We’re pros at keeping chimneys in good shape. Our chimney sweep in Los Angeles makes sure your home is comfy and safe. With over 15 years of experience, we’re licensed and insured.

Why choose us? Our expert team values safety, does a great job, and ensures your satisfaction. We’re really good at cleaning, fixing, and taking care of chimneys, making your home clean and safe. Our prices are fair, and our licensed and insured team responds quickly.

Pick us for the top chimney inspection and repair service in Los Angeles. We check your chimney, clean out anything dirty, and make sure everything is nice and tidy, giving you peace of mind and a cozy home.

Wrapping Up

To sum it up, learning “How to Fix Chimney Flashing Leak” is an important skill for homeowners to protect their homes from possible water damage. With the easy guide given, dealing with chimney flashing issues becomes doable, giving people the ability to keep their homes dry and safe. Don’t forget that taking care of your chimney is vital for keeping your home healthy and lasting a long time.


My new roof is leaking around the chimney. What to do?

If your new roof is leaking near the chimney, first clean the area well. Put lots of roof sealant on the edges of the flashing and check for damage. If you see any problems, repair or change the damaged flashing to stop water. Finally, check again to make sure your fix is good and will last.

How to reseal chimney flashing?

Clean the area, then apply roofing sealant generously along the chimney flashing edges to create a secure and watertight seal.

What materials are used for brick chimney flashing?

Common materials include metal (aluminum, copper, or galvanized steel) or specialized flashing made for chimneys.

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