Chimney Crack Repair
Not every crack in a chimney is serious, but some are, and from the ground they can look alike. The location and the pattern of a crack matter more than its width.
Where cracks appear and what they mean
| Where | What it often means |
|---|---|
| In the crown at the top | Weathering or shrinkage. Water enters through it. See crown repair. |
| Along mortar joints | Mortar failure. Often a repointing job. See repointing. |
| Through brick faces | Freeze damage or movement. See brick repair. |
| In stucco | Shrinking, impact or water behind it. See stucco repair. |
| In the firebox | Heat damage to firebrick or panels. See firebox repair. |
| In the flue | Heat or fire damage to tiles. See liner repair. |
| Stepped or widening across the chimney | Movement in the structure. This needs a careful look. |
Signs to take seriously
- The crack is getting longer or wider
- It runs through the brick as well as the joint
- The chimney is leaning, or has separated from the house
- Pieces are loose or have fallen
- There is water or staining beneath it
- It is in the flue or firebox, where heat and gases are involved
Signs that can usually wait
Hairline cracks in a crown or in stucco are common and often cosmetic at first. They still deserve to be sealed before water works in. Cracks in old mortar can be monitored if the brick is sound, though they are often a sign the joints are due for repair.
How we handle it
We inspect to find where the crack comes from, not only where it shows. A crack in the crown can mean the slab is deteriorating, and a crack in the masonry can mean water or movement. We explain which, and recommend the repair that fits it. If a crack points to structural movement, we tell you plainly, and explain what we can assess and what might need another professional’s opinion.
Hairline cracks that are sealed early often stay hairline cracks. Water entering a crack is what turns a small one into a repair.
What the work involves
How we approach cracks
- LocateWe find all of the cracks, including those that are hard to see from below.
- DiagnoseWe work out whether water, heat or movement caused them.
- ExplainWe tell you which are cosmetic and which need work.
- RepairWe repair the cause and the cracks.
Related services
Chimney Repair
The full range of repairs.
Learn moreChimney Inspection
Find where a crack comes from.
Learn moreChimney Leak Repair
When a crack is letting water in.
Learn moreWe work throughout New Jersey. See our service areas, or browse all services.
Questions
Frequently asked questions
Is a cracked chimney dangerous?
Some cracks are cosmetic. Cracks in the flue, or structural cracks that are growing, are not. We tell you which you have.
Can I seal a crack myself?
Surface sealant can slow water on a small crack, but it often fails and can hide a larger problem. We recommend having it looked at.
Why is my chimney pulling away from the house?
Movement or settlement can cause it. This needs to be looked at closely and we explain what we find.
How do I know if the crack is in the flue?
You cannot tell from outside. An inspection that looks inside the flue is how it is found.
Ready to have your chimney looked at?
Call us, or send a scheduling request. We will contact you to confirm a time. Your appointment is not confirmed until we do.