Chimney leaks are among the common issues people face. Such a situation is caused by many factors. To address the problem, you’ll need to identify these causes and apply appropriate remedies.

This article will show you everything you need to know about a leaking chimney.

Apart from showing you the possible signs and causes of chimney leaks, we’ll also provide information on what to do to stop and prevent a leak.

Time is of the essence when it comes to fixing the problem. The faster you respond to a leak, the less damaging it becomes.

Causes of Chimney Leaks and How To Fix them

The most common include damaged chimney crown, absence of a chimney cover, worn-out mortar joints & bricks, condensation, leaking chimney flue pipe, and faulty flashing.

Here are some of the events that result in problems with water seeping through on a chimney wall.

Chimney Leaks in Heavy Rain

Can water leak through a chimney? Yes.

Water getting into your chimney is a situation you’d rather avoid. Whenever you find leaks in your chimney, it could be due to several factors.

How do you stop a chimney from leaking? Let’s find out.

  1. Damaged Chimney Crown

Apart from protecting the masonry of a chimney, a chimney crown also helps to keep out water.

In other words, it helps prevent chimney leaks. So, when the crown is damaged, nothing is standing in the way of water penetrating your chimney.

The chimney crown mostly comes in the form of a slab. This is placed at the top of the chimney structure to prevent water leaks. So, what causes this damage? The continued action of weather on this slab gradually weakens it.

As a result, the chimney crown increasingly becomes brittle and degrades. Such damage results in chimney leaks.

To fix this problem, repairs or total replacement of the chimney crown is necessary.

  • Fixing the Damage

When a chimney leak is due to a damaged crown, there are two basic ways to solve the problem. The first involves filling up the cracks with mortar.

That way, water hardly penetrates or passes through the crown into your chimney.

The other alternative available for fixing this problem involves the total replacement of the chimney crown. This is usually the case when the crown gets damaged beyond repair.

  1. Absence of a Chimney Cover

A chimney cover is an important part of the chimney system. This component helps in keeping water and other unwanted stuff out of your chimney. It serves to cover the top of your chimney.

With a chimney cap in its proper place, you won’t have to be worried about water or snow getting in.

A chimney cap also serves to keep out animals from nesting in your chimney. Given its beneficial uses, not having one exposes your chimney to the elements, debris as well as animals.

Moisture or leaks resulting from the absence of a chimney cap is a situation you don’t want to deal with.

  • Fixing the Problem

We’ve seen that the absence of a chimney cap will lead to leaks.

Now, to fix this problem, you only need to have a new cap properly installed. Proper installation is necessary because chimney caps can be blown by strong winds among other things.

There are different sizes of chimney caps to choose from. It’s best to select the perfect cap size for your chimney.

  1. Worn Out Mortar Joints and Bricks

One of the likely reasons why you’re having chimney leaks may be due to worn-out joints and mortar. Both mortar and joints seep in water. Now, this wouldn’t be a problem if there wasn’t freezing and thawing during winter.

When this happens continually, it gradually weakens your chimney’s joints and mortar which in turn results in leaks.

For many people, one thing readily comes to mind; waterproofing the chimney.

Waterproofing has its advantages in stopping further chimney leaks However, there are downsides to it especially when the wrong waterproofing materials are used. During summer water absorbed gets naturally dried out with time.

Now, the problem arises for surfaces covered by sheds.

In such circumstances, it gets hidden from the sun which makes it hard to dry off. Nevertheless, trapped or soaked-in water will always find a way. This is likely to push its way down through a process known as “falling.”

Covering the chimney with the wrong waterproofing material affects the natural drying of trapped water within the pores of brick and mortar. To prevent this, you’ll need to get and use the right waterproofing material.

We recommend using waterproofing materials containing polysiloxane. Such hardly block brick and mortar pores thus ensuring water naturally escapes.

  1. Condensation

Chimney leaks due to condensation buildup are a problem you’re likely to encounter especially when a chimney gets converted to gas burning from wood burning. So, how does changing the type of fuel lead to leaks?

Condensation in such situations happens when there’s no proper liner. When a gas fireplace is being used, fumes are given off in the process. Such fumes contain moisture which at lower temperatures easily accumulates and gets absorbed into your chimney walls.

With a good liner, condensation wouldn’t pose much of a problem. However, the reverse is true when the liner isn’t good enough or absent.

  • Avoiding this Problem

There are ways to prevent chimney leads due to condensation. One of the easiest has to do with installing or fixing the right liner. The best way to get this done is by calling for professional help.

After inspecting the chimney, recommendations are given and the right liner is fixed.

  1. Faulty Flashing

Chimney flashing is a very crucial part of your structure through which the chimney penetrates the roof. It acts to keep water, and debris out from the roof.

Now, a faulty flashing won’t provide the needed protection. This leads to chimney leaks.

  • Fixing the Problem

Once leaks are noticed in your chimney and the problem is traced to a faulty flashing, it’s important to act fast. Immediate action is required to protect your roof and home from water damage.

Part of the repairs to be carried out on your flashing includes waterproofing. It is advisable not to carry out this repair task yourself. Call for professional help immediately. The sooner this is done, the better.

Identifying A Source Of Chimney Leak

Knowing the causes of a chimney leak is one thing; however, identifying the leak source is another. All of these are essential to finding and addressing a leakage.

Now, there are effective ways to pinpoint a chimney leak source. The following steps should help.

First, you’ll need to find a partner to help out in identifying chimney leak sources. This makes the process much easier. However for this process to be effective, certain tools are necessary.

Tools needed include walkie-talkies or cell phones for ease of communication, a roll of clear plastic for wrapping, and safety harnesses.

Additional tools included rubber-soled shoes, 2 water hoses (must have shut-off nozzles), as well as bright markers.

  • Wrapping

The process begins by wrapping the chimney using the role of clear plastic and starting from about half an inch above the flashing moving upwards.

  • Letting the Water Run

One person should be on the roof with the hose while the other should be inside. Now, turn on the hose and allow the water to run down for about 2 minutes. It is important to allow the water to flow down naturally.

Now, the person within the building has the sole task of identifying areas showing signs of water penetration. Such areas are marked using the bright marker.

  • Inspecting Other Chimney Areas

It is possible not to find any leaks at the lower end of the chimney. Now, move the water hose further up for more probing. Care must be taken to avoid letting the water get behind the chimney.

  • Continue this Process

This inspection goes on until all the chimney sides are covered. Any leaks spotted within are marked for repairs which should follow shortly.

Who To Call For Chimney Leak

The process of identifying a chimney leak isn’t suitable for everyone. Some people would rather have experts conduct this inspection on their behalf. So, you don’t have to get involved yourself as it can be stressful.

Hire a chimney specialist.

Call for expert help to find and fix chimney leaks. This is among the most comprehensive ways of fixing a chimney fault. It is important that you only choose professionals having the needed experience and expertise.

By so doing, the fix for a chimney leak lasts longer and you won’t have to frequently call to fix the same problem. The best possible way to find the right technicians for this job is by searching for online reviews.

This provides you with ample information on trusted chimney services nearest to your location.

Preventive Measures For Chimney Leaks

After a chimney leak has been successfully fixed, you can extend its lifespan by taking preventive measures. Such measures are varied. However, all are geared towards preventing water damage to your chimney.

One of the most reliable ways to keep your chimney free of leaks is by frequent inspections. You can easily ask for a scheduled inspection to be carried out at certain intervals


There you go! We’ve made information available about chimney leaks, the causes, and how to pinpoint such leakages. The information here will keep your chimney functioning in top shape.

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