Chimney repair fixes the masonry, mortar, and structure that keep your chimney safe and watertight. Common jobs include tuckpointing crumbling mortar joints, replacing spalled brick, rebuilding the crown or the chimney above the roofline, and sealing leaks. Caught early, most are small; left alone, they become rebuilds. Chimney Sweep Squad repairs and rebuilds chimneys across McHenry, IL. Call (815) 420-6665.
Why chimneys deteriorate here
Northern Illinois gives chimneys a hard time. Water soaks into brick and mortar, then our freeze-thaw winters expand it and crack the masonry apart — a process called spalling. Add a failing crown or cap and water pours straight into the structure. Once the mortar joints open up, the damage accelerates fast.
Repairs we handle
- Tuckpointing — grinding out failed mortar joints and repacking them with fresh, matched mortar
- Brick replacement — swapping spalled or cracked brick before water reaches the flue
- Crown repair & rebuild — resurfacing or recasting the concrete crown that sheds water off the top
- Partial & full rebuilds — rebuilding the chimney above (or below) the roofline when the masonry is too far gone
- Leak repair & waterproofing — flashing repair and breathable water repellent to stop intrusion
Our process
We inspect the full structure first — crown, cap, brick, mortar, flashing, and flue — so you understand exactly what is failing and why. Then we give you honest options, from a targeted repair to a rebuild, with upfront pricing. We match mortar and brick so repairs blend in, and we protect the rest of your home while we work.
What affects the cost
Price depends on the height and access of the chimney, how much masonry is involved, and whether the crown, flashing, or liner also need work. A few feet of tuckpointing is a modest job; a full above-roof rebuild is a larger one. We quote every repair after we see it.
Structural damage emergency
If your chimney is leaning, has large cracks, or is dropping brick, stop using the fireplace and keep people away from the area below it. Structural failure can be sudden. Call us to inspect, and see our emergency guide.
Frequently asked questions
Is it cheaper to repair or rebuild a chimney?
Repair is almost always cheaper when the damage is caught early — tuckpointing and brick replacement cost far less than a rebuild. A rebuild makes sense only when the masonry is so deteriorated that patching would not be safe or lasting. We give you both options honestly.
What is tuckpointing and do I need it?
Tuckpointing is grinding out crumbling mortar joints and repacking them with fresh mortar. You need it when the mortar between bricks is cracked, recessed, or missing. Failing joints let water in, which is what causes most serious chimney damage.
Why is my chimney leaking water?
Chimney leaks usually come from a cracked crown, a missing or damaged cap, failed flashing where the chimney meets the roof, or porous brick and mortar. We trace the actual source rather than just sealing over it, then repair and waterproof.
What does spalling brick mean?
Spalling is when brick faces flake, crack, or pop off because water soaked in and then froze. It is a sign water is getting into the masonry. Left alone, spalling spreads and weakens the structure, so damaged brick should be replaced.
Can you match my existing brick and mortar?
Yes. We match brick type and mortar color and mix so repairs blend with the original chimney rather than standing out. Mortar matching also matters structurally, since the wrong mix can damage older brick.
How long does a chimney repair take?
A small tuckpointing or crown repair is often a one-day job. Brick replacement and partial rebuilds take longer, and full rebuilds depend on height and weather. We give you a realistic timeline with your quote.
Is a leaning or cracked chimney dangerous?
It can be. A visibly leaning chimney, large vertical cracks, or gaps between the chimney and the house can signal a structural problem that needs prompt attention. Stop using the fireplace and call us to inspect it.
Do you waterproof chimneys after repair?
Yes, when it is appropriate. We apply a breathable, vapor-permeable water repellent that keeps rain out while letting the masonry dry. We never use a sealer that traps moisture inside the brick, which would make spalling worse.
Fix it before it becomes a rebuild
Small cracks and open mortar joints only get worse. Get an honest assessment and upfront pricing, 7 days a week.
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Published November 10, 2026 · Reviewed by Joseph Ino, Founder & Master Chimney Technician, Chimney Sweep Squad