What's In This Article
What an Above-Roofline Rebuild Means
An above-roofline rebuild is exactly what it sounds like: the chimney is dismantled down to roughly the point where it meets the roof, and rebuilt from there up. New brick, new flue tile, new crown, new cap, new flashing.
Everything below the roofline — the section running through the attic, through the house, down to the firebox — is left alone.
The question is obviously: why is that safe? And the answer is that the two sections of a chimney live in completely different worlds.
Why Only the Top Ever Fails
The portion of a chimney inside the house is protected. It's dry. It's temperature-stable. It's surrounded by conditioned space on all sides. It goes through essentially zero freeze-thaw cycles. Left alone, it can last as long as the house.
The four feet sticking up above the roof lives somewhere else entirely:
- 60–100 freeze-thaw cycles per Missouri winter. Water in, freeze, expand, thaw. Over and over.
- Full UV exposure on all four sides, year round.
- Wind loading with no lateral support above the roof line.
- Direct rain on the crown, which is the chimney's only horizontal surface and its most common point of failure.
So the failure is nearly always concentrated in the exposed section. When a mason tells you "the chimney is failing," ask them where. If the answer is "above the roof," you may be looking at a rebuild rather than a replacement — and the difference is many thousands of dollars.
A Rebuild, Start to Finish
The homeowner keeps their original chimney below the roof. They get a brand new one above it — which is the only part that was ever failing.
What Tells Us It's Time
- The crown is cracked or gone. Once the crown fails, water goes straight down into the top courses of brick. Everything after that is downstream.
- Bricks in the top courses are loose or missing. If you can move a brick by hand, mortar is no longer holding the structure together.
- Widespread spalling above the roofline. Faces flaking off across the exposed section means the brick itself is saturated and failing, not just the joints.
- A structural crack running down the exposed section. See our Maryland Heights crack case study for what this looks like and why patching it doesn't work.
- The chimney is visibly leaning or out of plumb above the roof.
If the joints are worn but the brick is intact, the crown is sound, and nothing is loose — you need tuckpointing, not a rebuild. We'll tell you that. It's a smaller job and a smaller invoice, and it's the honest answer.
The Numbers, Side by Side
Rebuild vs. Full Teardown
The spread between the middle row and the bottom row is why this article exists. A full teardown involves scaffolding the entire height of the house, demolishing masonry inside living space, and rebuilding a structure from the foundation up. It is occasionally necessary — if the chimney is failing below the roofline, or if the footing has moved, there is no shortcut.
But it is quoted far more often than it is necessary. If someone has handed you a $20,000 number, get a second opinion before you accept it. Ours is free, it's in writing, and it comes with photographs of what we actually saw up there.
Frequently Asked Questions
How much does an above-roofline chimney rebuild cost in St. Louis?
Typically $3,500–$8,500 depending on chimney size, the height above the roof, brick selection, and roof access. That compares with $15,000–$25,000 for a full teardown and replacement. Every estimate is free and in writing.
Is an above-roofline rebuild as good as a full replacement?
For the overwhelming majority of failing chimneys, yes — because the failure is in the exposed section. The masonry inside the house is protected from weather and freeze-thaw and typically remains sound. Rebuilding the failed part gives you the same result.
When do you actually need a full teardown?
When the failure extends below the roofline, when the footing or foundation has moved, or when the chimney is structurally unsound through its full height. That's genuinely rare, and it should be demonstrated to you with photos, not just asserted.
How long does an above-roofline rebuild take?
Most are completed in two to four working days depending on size, weather and cure time for the crown. We photograph each stage so you can see the work even though it's on your roof.
Is the rebuild warrantied?
Yes — AIO Pro Chimney backs the workmanship with a 10-year warranty. We're a CSIA Member and an NCSG Member.
Quoted $20,000? Get a Free Second Opinion.
We'll get on the roof, photograph what's actually there, and tell you honestly whether you need a rebuild, tuckpointing, or nothing at all.
