How Does Water Affect Your Chimney?

Posted on: 15 November 2022

When you think about problems with chimney masonry, you might not think much about water. Since many American homes only include brickwork for accents or specialized parts of the home, such as the chimney, many homeowners don't understand how to care for brick or how the environment may affect it.

Of course, water is often the most powerful environmental element faced by any part of your home. While brick is a highly durable material, it's not immune to the ravages of water. In many cases, chimney repairs often originate with one source: water ending up somewhere it doesn't belong.

Caps, Crowns, and Water Protection

Brick is a porous material that will absorb substantial moisture if given the opportunity. As a result, chimneys need protection from the elements, and it's particularly crucial to protect your chimney from standing water that may absorb into the bricks. This moisture can cause unsightly efflorescence or severely damage your masonry as it freezes and expands.

Common forms of water protection are caps and crowns, and there's a good chance that your chimney has both. A cap covers the flue itself, and it may include mesh or other protective elements to keep birds and critters out of your home. Caps stop water from entering the flue, but their primary role isn't to protect your brickwork.

On the other hand, the crown covers the entire top of the chimney. Depending on your chimney's design, your crown will likely be a large cement slab that extends over the edges. You may also have a metal cover that serves a similar purpose, although these are usually known as "chase covers" rather than crowns.

The Signs of Water Damage

In many cases, chimney problems originate with a failing crown. As the crown fails, it allows water to enter the chimney stack, where it can pool and saturate the brickwork. This excessive moisture will cause white powder ("efflorescence") to appear on your brickwork and may ultimately cause your bricks to crumble or fail.

These signs, along with dark spots or stains on your chimney bricks, strongly indicate that you may have a moisture problem. Fortunately, it's usually unnecessary to tear down and replace a chimney due to water damage unless the problem is severe. Instead, contact an experienced chimney repair contractor as soon as you notice these issues.

In most cases, you can resolve the problem by repairing the underlying cause of moisture intrusion, such as a failing crown. Once you've fixed the underlying cause, you can work with a masonry repair expert to restore your brickwork and get your chimney looking like new again. 

For more info about chimney masonry repairs, contact a local professional.