A Tilting Chimney Can Be a Sign of Foundation Problems

Have you noticed that your chimney seems to be leaning off center? If you take a closer look and notice that there is a gap between the chimney and the siding of your house, it is a clear indicator that your eyes aren’t playing tricks on you: your chimney is tilting. You might have to climb up into the attic to get a closer look if your chimney runs through the interior of your house instead of along the exterior. In that case, you will know if it is leaning if it isn’t centered in its frame but is instead pressing on one side or the other.

A tilting chimney can pose a serious health and safety risk whether it runs along the exterior of your home or through the interior of your home. Masonry chimneys are extremely heavy, weighing many tons. All of this weight is concentrated on a very small area: the footing. If the problem is not solved, it could collapse potentially crushing someone underneath it or destroying your roof. Even in the best-case scenario, water and bugs will be able to get into the gaps between the chimney and your home. The shifting chimney may also crack the flue liner exposing your home to toxic gases from the fireplace, like carbon monoxide, and creating a greater risk of a house fire.

What causes a chimney to tilt?

There are two different types of problems that cause a chimney to tilt: structural and foundational.

If the top of your chimney is leaning over your house, as if it might fall through your roof, the cause it most likely a structural problem. Structural problems are commonly caused by water damage that has deteriorated the mortar joints and bricks. The best solution is to call a mason or chimney professional like us to repair it. We will be able to shore up the existing frame and replace the failing bricks and mortar to restore the integrity of your chimney.

If the chimney is leaning away from the house, as if it might crash into the yard, the cause is most likely a foundational problem. The concrete footing, or chimney pad, at the base of the chimney is what sustains all of its weight. If the footing fails, the entire chimney will be less stable.

These are the most common causes of foundational problems that we come across:

– Deteriorated footing: If moisture penetrates the footing and it goes through a cycle of freezing and thawing it will eventually deteriorate. It may also crack if it was made with poor quality concrete or lacks rebar reinforcement.

– Wrong sized footing: The footing for a chimney should extend out at least 6 inches from all sides and be at least 1 foot thick. If it is too small, the chimney will eventually begin to lean.

– Poor soil quality: If the footing was poured in expansive soil (soil that contracts and expands when the water content changes) or loose soil it will not provide a solid enough foundation for the chimney. Backfilled soil and erosion can also cause issues that weaken the support of the chimney.

– Missing footing. If the chimney was built without a footing then it will be unstable and one will need to be poured beneath it.

If the problem is foundational, the chimney will need to be supported and the footing will need to be repaired or poured by a chimney professional.

Give us a call if you notice that your chimney is leaning! We will send one of our chimney experts from Guardian Chimney Sweep to your home to pin point the exact cause and let you know the best solution. We are happy to help homeowners throughout the Houston, TX area preserve the integrity of their homes. You can reach us at (713) 401-2011.