Get New DIY Projects Delivered Weekly - Sign up for Our Newsletter Today!

How to Repair Cracks And Maintain Your Chimney

How to Repair Cracks And Maintain Your Chimney

Win a
$1,000 Milwaukee Tool Package

Get a chance to win a full kit of Milwaukee branded tools. For slow Saturdays, half-built shelves, and everything in between. No purchase necessary.

If you've been wondering how to tend to your chimney without the help of hiring a chimney sweep, the pro James Dulley is here to discuss some great tips. In this article, James talks about how to repair cracks and maintain your chimney.

How to Repair Cracks And Maintain Your Chimney

Dear James:

After using my wood-burning fireplace often this winter, I have found some long cracks in the brick and mortar outdoors. Is this something that needs immediate attention? — MaryAnn L.

Dear MaryAnn: Generally some minor cracks in a chimney mortar between bricks are common, but the long cracks you described might indicate a serious problem. The fact that the cracks continue through the mortar and the bricks is what you should be concerned about.

Rust-Oleum 301012 Concrete Patch & Repair, 24 oz, Gray
  • Ideal for indoor/outdoor use to repair concrete cracks and holes in concrete
  • Two-part, industrial-strength epoxy permanently bonds concrete without shrinking or cracking

Chimney problems should not be ignored. A typical masonry chimney weighs many tons and many have been known to collapse. This can do a lot of damage. Also, since you use the fireplace often, a faulty chimney can result in a fire hazard. Fireplace problems are one of the leading causes of fatal house fires.

It would be wise to have your chimney professionally inspected. Your first step might be to call a chimney sweep to have the chimney cleaned. Although they are not structural engineers, an experienced chimney sweep has seen most of the problems that can occur with a chimney. He/she may recommend you contact a licensed structural engineer to evaluate it.

Bricks and mortar create an extremely strong structure because they have tremendous compressive strength of thousands of pounds per square inch. To the contrary, they are relatively weak when they are stretched in tension. If the chimney begins to tilt at all from being unevenly supported, this puts some of the bricks and mortar into the weaker state of tension instead of compression as it was designed to be.

There are several possible causes of the chimney cracking problems you are experiencing. A chimney, due to its extreme weight, should have a large concrete footer beneath it to support it. Code usually requires a chimney footer to be at least one foot thick and extend out a foot or more further out than the chimney. Check your building plans for the size of the footer.

The footer should have been reinforced with steel rods (called rebar) when it was poured. Even if it is large enough, if the concrete was not adequately reinforced or there was a problem with the strength of the concrete mixture, the footer may be disintegrating from the weight of the chimney.

3M Bondo Wood Filler 30 oz (850.49 g) with Bondo Cream Hardner 0.5 oz (14g), Repairs Chips and...
  • TWO-PART FORMULA chemically bonds with surface to adhere permanently
  • QUICK, DURABLE REPAIRS to damaged and rotted wood

Settling of the ground beneath the chimney footer is another possibility. If your house was built on fill, then the footer, even though it was properly sized, may be rocking or sinking deeper. If it moves, even a small amount, the stresses in the heavy chimney can be tremendous.

Another less likely possibility is faulty bricks. If several weak bricks were placed on top of one another, unusual stresses could have caused them to break. Once several of them break, it may create additional stresses on the other bricks. The structural engineer will be able to test this for you.

Abatron Krack Kote - Drywall and Plaster Repair Kit with Acrylic Emulsion and Polyester Mesh...
  • RESTORE DAMAGED WALLS AND CEILINGS: Make invisible, permanent repairs to cracked ceilings with this...
  • SPECIALLY FORMULATED: The all-in-one drywall repair kit contains an acrylic emulsion, an easy-to-use...

Whether you are able to repair the chimney or you have to totally rebuild it, consider installing a chimney cap and a metal flue liner. The cap will keep debris, rain and animals from getting into the top of the chimney. The liner will minimize the possibility of future chimney fires from creosote buildup. The liner will also make it easier for a chimney sweep to keep it clean.

Send your questions to Here’s How, 6906 Royalgreen Dr., Cincinnati, OH 45244 or visit www.dulley.com.

To find out more about James Dulley and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com. COPYRIGHT 2017 CREATORS.COM

Leave a Comment

Your email address will not be published. Required fields are marked *

Everything you need to complete your next weekend build, straight to your inbox.

SIGN UP FOR WEEKLY INSPIRATION

Get fresh project ideas and expert tips sent to your inbox weekly!

Win a
$1,000 Milwaukee Tool Package

One winner walks away with approximately $1,000 in Milwaukee branded products, shipped Via Amazon. Closes May 10.

Related Articles

Win a
$1,000 Milwaukee Tool Package

Get a chance to win Milwaukee tool branded products for your next home project. 
Free to enter, ends May 10.
Scroll to Top