Why crowns crack
Plenty of crowns were never built to last: mortar troweled on thin, finished level so rain pools on it, with no overhang to throw rain clear of the brick. Water soaks in, freezes, expands and thaws again many times each winter. Each cycle opens the cracks a bit more, until pieces start breaking off.
Repair or rebuild
When the crown is sound apart from hairline cracks, we clean the cracks out and seal them. That's a repair, usually $700 to $1,400 depending on the size of the chimney.
If the crown is broken into pieces, sits loose on the brick, or has been patched so often that the patches are failing, we break it off and pour a new one. A rebuild runs $1,000 to $4,000.
What sets the price
Where a job lands in the range depends on how big the chimney top is, how many flues come through it, the roof's pitch, and how high the chimney stands. If the cap has to come off, or loose brick under the crown has to be relaid first, that's written into the quote too.
What we check first
Before quoting, we look at the brick just under the crown. When water has been getting in for a while, the top few courses can be loose too, and that turns a crown job into a partial rebuild.
How a new crown goes on
- Tarps and boards go over the roof, and the flue openings get covered.
- We break the old crown away until we reach sound brick.
- We build a wooden form around the chimney top and pour the new crown inside it, sloped away from the flues and extending past the brick on every side.
- We seal around the flue tiles and set the cap back on, or fit a new one if the old cap has rusted.
Signs of a failing crown
- Cracks visible from the ground or a ladder
- Chunks of concrete in the gutter or on the roof
- Damp patches or stains indoors next to the chimney
- Moss or plants growing on top of the chimney
