Chimneys Weather Protection Useful Guide!

How often do you think about your chimney? If you’re like most, probably not often enough. In our experience, the chimney is typically the least noticed part of a home, but there’s more to a chimney than its simple design. The reason so many of us don’t worry about our chimneys is because they function well and do their job at a minimum even when they’ve been neglected. 

Let’s take a look at a few of the ways that weather can damage your chimney, the worst case scenarios, and how you can make sure the worst doesn’t happen to you or your family. 

Why worry?

There’s more than meets the eye here, and chimneys are so much more than just passive black holes that direct smoke and steam out of your house. The construction of a chimney is complex, and it’s almost a work of art the way that they are put together. If your chimney is subject to constant weather abuse, eroding and corroding over the years, you might be in for a nasty surprise (and repair bill) sometime in the future. 

What is a Masonry Chimney?

3What is a Masonry Chimney | Alexander and Xavier Masonry

Constructed from a variety of different masonry and metal materials, a masonry chimney helps direct smoke and steam from your fireplace to the outside of your home. Typically, masonry chimneys can be built from brick, concrete, mortar, concrete block, flue tile, steel, and even cast iron. Most of these materials are negatively affected by water and water penetration.

Understanding Water Penetration

Water negatively affects every piece of the masonry chimney aside from stone. Deterioration is the most common effect of prolonged water contact and masonry materials will deteriorate even quicker because of the freeze/thaw process of water penetration. The water that penetrates the materials freezes, which means it expands and puts the materials under stress. Also, water in the chimney also causes metals to rust, which weakens or even destroys them, necessitating a complete replacement. 

Keep in mind that while water penetration doesn’t affect most stone, tons of mortar is needed for construction, meaning that a stone chimney needs just as much protection as other types of chimneys.

Is your chimney at risk? Here are the common effects of water penetration to be on the lookout for:

If those side effects aren’t bad enough, when the water mixes with creosote in a wood burning fireplace, the smell is pretty nasty, and it can fill your entire home. If you notice any stinky-ness coming from your fireplace, it’s time to call in the chimney experts.

Another thing you need to know is the fireplace and chimney cost. This is an important knowledge in order to keep away from overpriced contractors.

How to Prevent Water Damage in Your Masonry Chimney

Chimney Water Leak | Alexander and Xavier Masonry

The most inexpensive option is to use a chimney cap or rain cover. For years, chimney caps have been recognized as the inexpensive, easy, and essential chimney safety and damage prevention component. They help to keep water from dumping directly into the chimney, cutting down on water penetration significantly. 

Because chimneys typically have one large opening known as the flue, water from rain or snow can dump directly into the flue and it will collect in the chimney interior. Even the most common-sized flue can let in a ton of rain and snow over the winter, which is why a cap is crucial.

Maintaining chimney caps also do more than just block rain and snow from dumping into the opening as a well-designed chimney cap will keep more out of your flue, including birds and other nesting animals that will block your chimney. A cap will also function to keep any stray embers or sparks from leaving your fireplace and landing on combustible material on the roof. 

The best chimney caps will be easy to remove for inspection by a local chimney sweep or cleaning service provider. They should also be made of durable materials that will hold up over time. You can get caps to cover a single flue or multiple flues and large parts of the chimney itself too. Although they might require a big upfront invest, the protection is well worth it.

Another thing to check is the chimney shoulder. The chimney starts to narrow as the masonry is higher, the slope often feature ledges that prevent rainwater from draining away from the brick and stone. Water and mortar can lead to degradation over a period of time.

Don’t missed out our article about ways on how does chimney shoulder repair helps your chimney to be waterproof.

We at Alexander and Xavier Masonry do the job with passion and swiftness, so you know that your chimney is in good hands.

The Damaged Chimney Crown Repair and Replacement Process

The chimney crown is the top element of a masonry chimney. It’s also known as a “chimney wash” too. Regardless of how it’s known, this piece covers and seals the top of a chimney from the flue liner. Ideally, the chimney crown will have a downward slope to direct water from the flue to the edge of the chimney crown. This helps to prevent erosion of the mortar and brick in the vertical surfaces of the chimney itself. 

When first built, many chimneys have an inadequate crown. This is because some builders will cut corners to save costs, using a common mortar mix that cracks, chips, and deteriorates from weather exposure alone. The crown should be constructed with a Portland cement-based mix that is cast and/or formed with a minimum two-inch overhang beyond all sides of the chimney.

Repairing Deteriorated Mortar Joints

Water first enters the chimney via the mortar joints of the exterior of the chimney. If done right, the mortar joints won’t have any gaps to let water seep in and they’ll be shaped to direct water out of the joint. If the mortar deteriorates enough, it becomes highly absorbent.

To repair most common issues, your masonry chimney repair service will repoint the joints. The repointing process is when the existing mortar joint is recut to an appropriate depth and then repacked with new mortar. They will then cut this new mortar in a concave shape so it can naturally redirect water away from the joint. If done well by an experienced team, they’ll increase the life span of the chimney and even enhance the appearance too. 

Repairing and Replacing Flashing

Flashing seals any gaps between the roofing material and the chimney itself, preventing rainwater and snow from leaking down the chimney into your living spaces. This joint expands and contracts between the roof and chimney naturally, allowing the materials to move and “breathe” on their own without breaking the waterproof seal. 

A Cricket Helps to Stop and Prevent Leaks

If your chimney is located on the low side of your roof, you’ll need a cricket installed for additional water protection to keep water from leaking into your home. Crickets serve to redirect water away from the chimney and are recommended for chimneys more than 30 inches wide and chimneys on, especially steep-sloping roofs.

However, if you experience a chimney leak problem, it would be best to call a professional to avoid further damages.

Why and How to Waterproof Your Chimney

Most of the masonry materials used in chimney construction are porous to begin with. They absorb tremendous amounts of water, which isn’t ideal for waterproofing. What’s more, if the mortar joints aren’t constructed properly, they only accelerate the water damage to the chimney. For these reasons alone, waterproofing is a must if you want to extend the life of your chimney and avoid any costly repair bills in the future. 

There are several products available to waterproof chimneys. Many of the formulas are 100% vapor permeable and allow the repaired chimney to breathe, expanding and contracting naturally. So, when water enters the joints and eventually evaporates, the joints are moveable and this can cut down on cracking and erosion. 

When it’s all said and done, waterproofing is a preventative measure that every homeowner should look into. Even if you haven’t experienced a problem yet, it only takes one bad storm to cause severe damage to your chimney. Work with an experienced team and they’ll provide a custom solution for your chimney to keep it ready for any weather.


As the winter season is upon us, now is the time to ensure your chimney is protected from snow, rain, and other environmental damage. If you are unsure if you’re protected, get in touch with our chimney repair service experts and we’ll provide and inspection and perform repairs and restorations to ensure your chimney is ready for everything Mother Nature has to throw at it. 

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