Why Do Chimneys Lean Away From the House?

A leaning chimney is one of those things you notice out of the corner of your eye one day: a gap opening between the chimney and the wall of the house, or a stack that just does not look straight anymore. It is worth taking seriously. A chimney holds thousands of pounds of brick and mortar, and when it starts to lean, it is telling you that something underneath it has moved.

Your chimney stands on its own

Here is the part most homeowners do not realize. In a lot of houses, the chimney is built on its own separate footing, apart from the main foundation of the home. That means it can settle and move on its own, independent of the rest of the house. When the ground under that footing gives way on one side, the whole stack tilts with it.

Chimneys lean in two different directions, and each one means something different.

Leaning away from the house

When a chimney pulls away from the house and leaves a widening gap, it is almost always the foundation. The footing under the chimney is sinking into soft soil along its outside edge, and as it drops, the chimney tips outward. The further it leans, the more weight shifts onto that low side, and the faster it keeps going. Left alone long enough, a chimney leaning outward can come away from the house entirely.

Leaning into the roof

A chimney that leans in toward the roof is usually a different story. These are often chimneys built on interior walls that were never meant to carry that kind of weight, leaning on the roof framing for support that was never enough to begin with. That one is about how it was built, not about the soil.

Warning signs

• A gap between the chimney and the side of the house, usually wider at the top
• Stair-step cracks in the brick or mortar of the chimney
• Cracks on the inside wall where the chimney passes through the house
• Daylight or a draft where the chimney meets the wall
• A chimney that simply looks tilted next to the roofline

Why patching it does not work

You can fill the gap with caulk or repoint the cracked mortar, and it will look fine for a season. But if the footing underneath is still sinking, the gap opens right back up. The lean is a foundation problem showing itself up high, so you have to fix it at the base.

How we fix it

This is work we have done for decades, and it is one of the things that sets us apart, because most companies will only offer to tear the chimney down and rebuild it. We do not. We stabilize the footing with steel piers driven down to solid ground, which stops the sinking and, in many cases, lets us bring the chimney back toward straight. Then our own masons repair the brick and mortar the movement cracked and match the existing masonry so it looks right again. One crew, structure and brick both, no teardown.

If your chimney is leaning, do not wait on it. The lean only gets worse, and the sooner we catch it, the more of the original chimney we can save. See how we handle it on our leaning chimney repair page.