Why is My Chimney Leaking & How to Fix It?

August 30, 2023
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why is my chimney leaking

A leaking chimney can be a major problem. It can cause water damage to your home, lead to mold growth, and even create a safety hazard. If you have a leaking chimney, it’s important to fix it as soon as possible.

In this blog post, we’ll discuss the most common causes of chimney leaks and how to fix them. We’ll also talk about the importance of hiring a professional to fix a leaking chimney.

Why Chimney Leaks When it Rains : Common Causes

Damaged Flashing

Flashing is like a protective shield that covers the area where your chimney meets the roof. If it’s broken or not properly installed, rainwater can sneak through the gaps.

Cracked Masonry

The bricks and mortar that make up your chimney can crack over time due to weather and age. These cracks can let rainwater seep into your chimney.

Crumbling Crown

The crown sits on top of your chimney and helps keep rain out. If it’s damaged or deteriorating, water can find its way in.

Missing Chimney Cap

Think of a chimney cap like an umbrella for your chimney. If you don’t have one or yours is damaged, rain can easily get inside.

Absorbing Water

Sometimes, the bricks and mortar of your chimney can absorb water like a sponge. This can lead to leaks, especially during heavy rain.

Knowing these common causes can help you figure out why your chimney is leaking when it rains. Once you understand the problem, you can take steps to fix it and keep your chimney dry.

How to Diagnose Chimney Leaks

Chimney leaks can be frustrating, but figuring out where the water is coming from is the first step to fixing the problem. Here’s a straightforward guide to help you diagnose chimney leaks:

Visual Inspection

Take a close look at your chimney, both from the outside and inside your home. Check for any signs of moisture, water stains, or discoloration on the walls, ceiling, or around the fireplace. 

The Flashlight Test

On a sunny day, turn off the lights inside and use a flashlight to inspect the interior of your chimney. Look for any spots where light shines through gaps or cracks. This can give you a clue about potential leak points.

The Hose Test

On a dry day, grab a hose and ask someone to help you. Start by spraying water on different parts of the chimney, starting from the bottom and working your way up. Keep an eye on the inside for any signs of water seeping in. Pay close attention to the flashing, masonry, and crown.

Check the Attic

If your chimney runs through your attic, head up there during or after rain. Look for any signs of dripping, dampness, or water stains around the chimney area. This can help you identify where the water might be getting in.

Check the Roof

Inspect your roof around the chimney area. Look for any damaged or missing flashing, shingles, or tiles. If you see any issues on the roof, they might be contributing to the leaks.

Observe During Rain

During the next rainstorm, observe the chimney area for any immediate signs of leaks. Check for dripping water or damp spots. This can provide real-time clues about the leak source.

Remember, diagnosing chimney leaks might require some detective work, but it’s an important step to solving the problem. Once you’ve identified the source of the leak, you can take the necessary steps to fix it and keep your chimney dry and your home cozy. 

If the issue seems complex or beyond your expertise, consider consulting a professional chimney technician for further assistance.

If your chimney is leaking, don’t worry – there are simple steps you can take to stop the water from coming in. Here’s how you can fix chimney leaks:

Fixing Chimney Leaks: Easy Solutions

Repairing Flashing

Flashing is like a protective jacket for your chimney where it meets the roof. If it’s damaged or not fitting well, rainwater can sneak in. You can fix this by adding new flashing or sealing the gaps with special waterproof materials.

Sealing Cracks and Gaps

If you notice cracks in the bricks or gaps in the mortar, these can let water in. You can use a special sealant to fill these spaces and keep the water out.

Chimney Cap Replacement

If your chimney cap is missing or broken, it’s like leaving the door open for rain. Get a new chimney cap – it’s like an umbrella for your chimney, stopping rain from getting in.

Checking the Crown

The crown sits on top of your chimney and helps keep rain out. You can fix this by applying a special crown sealant to keep the water away.

Using Waterproof Sealant

Consider applying a waterproof sealant to the outside of your chimney. This creates an extra layer of protection, like a raincoat, to keep the rain from seeping in.

Getting Expert Help

If the leak seems tricky or you’re not sure what to do, don’t worry! You can call a professional who knows all about chimneys. They can find the problem and fix your chimney.

What is placed around a chimney to prevent leaks?

Roof flashing is placed around a chimney to prevent leaks. It is a metal sheet that is installed at the point where the chimney meets the roof. The flashing helps to seal the joint between the chimney and the roof, and it directs water away from the chimney.

There are two main types of roof flashing: step flashing and counter flashing. Step flashing is used when the chimney is installed on a sloped roof. It is made up of individual pieces of flashing that are installed in a step-like pattern. Counter flashing is used when the chimney is installed on a flat roof. It is a single piece of flashing that is installed under the shingles around the chimney.

In addition to roof flashing, a cricket may also be installed around a chimney. A cricket is a small roof structure that is built behind the chimney. It helps to divert water away from the chimney and prevent it from pooling behind the chimney.

By installing roof flashing and a cricket, you can help to prevent chimney leaks and protect your home from water damage.


A leaking chimney can be a major problem, but it’s one that can be easily fixed. If you have a leaking chimney, don’t delay in getting it fixed. The sooner you fix the leak, the less damage it will cause.

If you think you may have a leaking chimney, it’s important to have it inspected by a professional chimney sweep or repairman. We are providing professional chimney cleaning & repairing service in Los Angeles, CA, if you need any help contact with us. Our expert team has years of experience and uses advanced equipment to ensure top-notch service and customer satisfaction.


Can I fix a chimney leak myself?

Depending on the severity, you may be able to fix simple issues like sealing cracks. However, it’s best to consult a professional for complex repairs to ensure they’re done properly.

Can a damaged chimney crown cause leaks?

Yes, a cracked or damaged chimney crown can allow rainwater to seep into the chimney structure. Repairing or sealing the crown is essential to prevent leaks.

How often should I inspect my chimney for leaks?

It’s recommended to have an annual professional chimney inspection to catch potential issues early and prevent leaks.

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