Is My Chimney Leaking? (Several Clues That Say It Is)

A chimney leak can happen during any time of the year. The only time that you might actually notice a chimney leak is in the spring. This is because of the high amounts of rain we get during the spring months. This makes leaks much easier to detect for homeowners. Otherwise, leaks aren’t usually noticeable to homeowners. This is because most people have no idea where to look and what to look for. They also don’t know what’s causing the problem. With that being said, we’ve provided a guide below to help you detect a chimney leak and even prevent one.

What Causes Chimney Leaks?

The simple brick or stone chimneys you see are actually quite intricate structures that contain several different pieces and parts. Chimneys are constantly exposed to elements, so there’s a higher chance the masonry will become damaged and break down. Here are a few of the usual causes of chimney leaks:

Damaged Masonry:

Part of your chimney is directly exposed to rainfall and maybe other sources of water time and again. So, it puts the masonry at great risk. The masonry can become damaged or deteriorate a lot quicker than the rest of the chimney. The bricks can crack and spall because of the water, and even affect your chimney’s structural stability. This not only leads to chimney leaks but also makes your chimney look unkempt and aged. 

Improper Fitment of Your Chimney Cap:

A chimney cap is what protects the top of your chimney’s flue from animals, debris and even water entry. If the chimney cap isn’t properly fitted, then the flue and fireplace are left with high exposure to water entry. 


Flashing is the watertight strips that seal the seam between your roof and the chimney structure. Water can easily seep through any openings. This happens if the flashing is damaged, installed incorrectly or simply loses its seal from aging or wear and tear. This can lead to the chimney and roof, and the walls and ceilings surrounding the chimney, to suffer water damage.

Is My Chimney Leaking? (Several Clues That Say It Is)

The source of your chimney leak could be coming from the outside or the inside. It’s common for homeowners to mistakenly assume that chimney leaks will appear as visible water in the flue or fireplace. Yes, chimney leaks can be as obvious as puddles left in your fireplace. However, it can also be completely obscure and unrecognized until it has already caused significant damage to your chimney. Here are some signs that could indicate that your chimney is leaking:

  • Rusted parts
  • Drop inefficiency
  • Water or condensation inside the firebox
  • Mildew, musty or moldy odors especially after it rains
  • Sounds of dripping water or visible evidence in the chimney 
  • Leaks or moisture in other areas within the house, or water staining on the ceilings or walls surrounding the chimney

Your chimney may also be spalling, meaning the surface of the brick is flaking away. It will look broken or cracked and even have bricks missing. You can visually inspect the bricks of your chimney. See if there are any pieces of stone or bricks on your roof or surrounding area. 

Another sign of a leaky chimney is efflorescence. This is much easier to spot, as it appears as a white residue on the bricks of your chimney. Not only can this white residue occur due to the rain, but also due to condensation forming within your chimney. 

Preventing Chimney Leaks From Occurring

The most effective way to prevent a leaky chimney is to have preventive maintenance on your chimney and fireplace. It’s crucial that you get this maintenance done regularly. Get annual inspections and chimney sweepings done often to identify any recent damage to your chimney or masonry. This will allow you to have your chimney repaired before resulting in a leaky chimney. 

You could also have your masonry waterproofed. This requires applying a specialized sealant that keeps water out and still allows the masonry to keep its semi-porous nature. Even if your chimney has previous water damage, you can still apply these products to keep your chimney from worsening. 


If you have a home with a chimney, and a leak in your house, call a certified chimney mason immediately! They know where to look and how to stop the leaking. Ray Arnold Masonry is a team of professionals who are experienced in chimney diagnosis and treatment. We work to prevent them with our effective techniques. We will not only identify the leak but fix any damage that occurred and eliminate the problem as well. For our services, visit our website or contact us today for more information.