The crown covers the masonry from the outer edge of the brick to the flue tile. Sound, it sheds rain clear of the chimney; cracked, it lets water into the gap around the flue and the top courses of brick.
Chimney4u looks at the crown up close, explains which repair it needs and why, and sends a written scope and price first. Work begins only after you sign off on it, and the before-and-after photographs stay with you.
Common crown problems
Cracks in the slab or around the flue
Cracks often radiate from the flue tile or run to the corners. They tend to widen as water works into them.
A mortar wash instead of a crown
Many older chimneys have thin mortar troweled over the top bricks. Unreinforced and weak in tension, it tends to crack again however often it is patched.
No overhang or drip edge
A crown that ends flush with the brick sends runoff down the face and soaks the top courses. It should project past the brick so water drips clear.
Crumbling edges or damp top courses
Chunks of crown in the gutter, a thin edge breaking away, or flaking brick near the top can all mean water is getting in. Flaking brick has other possible causes too, so the whole top is checked.
The parts named on this page, from the cap and crown at the top to the flashing where the chimney meets the roof.
Sealing, resurfacing or recasting
Sealing isolated cracks
A sound, well-shaped crown with a few narrow cracks can have them cleaned out and filled with flexible masonry sealant. It suits only a crown that already sheds water.
Resurfacing a sound crown
Where the slab is solid but crazed across its surface, loose material comes off and a flexible crown coating is built up. A coating renews the surface; it cannot add slope, overhang or a drip edge.
Recasting a failed crown
A crown that is broken through, delaminating or a worn-out mortar wash is removed to sound brick with the flue covered. A new reinforced slab is cast with a fall away from the flue on every side, an overhang and a drip in the underside.
An expansion joint at the flue
The crown is kept apart from the flue tile and the gap finished with flexible sealant, so the flue can move without cracking the slab. Washington’s residential code calls for a caulked separation around flue liners on a masonry chimney.
The cap, checked at the end
The cap should shed water clear of the new crown, not onto it. If it needs replacing, see cap installation.
Materials for a damp climate
Sealants, coatings and concrete mixes are chosen for masonry that stays damp much of the year, not pulled from a generic spec.
When to inspect the whole chimney first
The crown is assessed in the inspection that comes before any quote. Start with a broader chimney inspection if water shows up indoors, the top flue tile is cracked or has dropped, or the upper brick is loose or leaning.
If the flue needs a new tile or relining, decide that before a new crown is cast. The crown is built around the flue.
Crown or cap: two different parts
The crown is masonry, a concrete or stone slab across the chimney top; the cap is a metal hood with mesh sides that sits above the flue. Quotes and even codes sometimes call both a “cap,” so ask which one a price means.
A cap keeps rain and animals out of the flue, while the crown keeps water out of the brick and the space around the flue. Replacing one never makes up for a failure in the other.
Water still getting past a sound crown may be coming through flashing or joints; see leak and flashing repair. Spalled or loose brick under the crown moves the job into masonry repair or rebuilding.
What affects the cost of crown repair
The first question is which of the three repairs your crown needs. After that, these matter most.
- Seal, resurface or recast
- The three differ greatly in labor and material, and the crown’s condition and shape decide which applies.
- Size and number of flues
- A wider chimney means more slab, and each flue through the crown adds a joint to detail.
- Access
- Roof pitch, height and roofing affect how the top is reached and the old crown brought down.
- What is under the old crown
- Spalled brick or open joints found once it is off must be made sound first, priced separately and only with your approval.
- Cast in place or precast
- A cast crown needs forms and suitable curing weather; a precast slab is made to measure and set in place.
You get a written scope and price before any repair work begins.
Why crowns work hard in the Puget Sound region
In the Puget Sound lowlands a crown’s main job is shedding rain, not carrying snow. At Sea-Tac Airport, NOAA’s 1991–2020 climate normals record only 6.3 inches of snow in a normal year, while about three quarters of annual precipitation falls from October through March. Crowns in the foothill and valley communities, which run colder and wetter than the airport, have a harder time of it.
The station also normally accumulates 4,375.8 heating degree days a year, a sign of a long heating season. For a chimney in regular use, that means many rounds of the flue warming and cooling inside a crown that is often wet, one reason the flue joint matters as much as the slab.
Masonry soaks up some rain and dries afterward, and problems start when drying never catches up. A crown that throws water clear of the face gives the brick below that chance.
Questions about chimney crown repair
Can a cracked crown just be sealed?
Sometimes. Sealing suits a solid crown that already has slope and an overhang, with a few narrow cracks. If the slab is breaking up or was built flush with the brick, sealant only postpones the decision, because it cannot add the missing shape.
Why does my crown keep cracking around the flue?
Often because it is mortared solid to the flue tile. The tile moves with heat and the crown does not, so a rigid joint cracks again after each patch. The remedy is a separation finished with flexible sealant, not more mortar.
What should a well-built crown look like?
Published crown guidance describes a cast or precast slab at least 2 inches thick, reinforced, kept apart from both the brick and the flue liner, and overhanging the chimney by 2.5 inches with a drip edge. Brick Industry Association detailing for masonry caps and copings adds a slope of at least 15 degrees and a drip whose inner lip sits at least 1 inch out from the wall face.
Do I need a permit for crown work?
That turns on the chimney, the extent of the work and where the house is. Inside Seattle city limits, SDCI generally requires a building permit before a structure is altered or repaired, work must meet code even when no permit is required, and the current rule for repairing masonry chimneys is SDCI Director’s Rule 07-2025, effective January 8, 2026. Other cities and the counties have permit offices of their own; whichever one covers your address, SDCI included, is where to confirm the requirement before work begins.
Sources for the facts on this page (9)
- Chapter 10 Chimneys and Fireplaces - Washington State Residential Code 2021 — UpCodes (reproducing the Washington State Residential Code 2021, based on IRC 2021). Accessed 2026-08-27.
- Four Low-Cost Recommendations to Prevent Major Water Damage — Chimney Safety Institute of America (CSIA), dated June 11, 2010. Accessed 2026-08-27.
- Fixing Leaky Chimney Systems (Part 2 - Crowns) — SaverSystems (ChimneySaver), article by Stuart Karanovich, April 3, 2025. Accessed 2026-08-27.
- Technical Notes 36A - Brick Masonry Details, Caps and Copings, Corbels and Racking — Brick Industry Association. Accessed 2026-08-27.
- Fixing Leaky Chimney Systems (Part 1 - Water Intrusion) — SaverSystems (ChimneySaver), article by Stuart Karanovich, April 3, 2025. Accessed 2026-08-27.
- U.S. Annual/Seasonal Climate Normals 1991-2020, station USW00024233 (seasonal precipitation) — NOAA National Centers for Environmental Information (NCEI). Accessed 2026-08-27.
- U.S. Annual/Seasonal Climate Normals 1991-2020, station USW00024233 (full record) — NOAA National Centers for Environmental Information (NCEI). Accessed 2026-08-27.
- 2021 Seattle Residential Code, Chapter 1 Scope and Administration — Seattle Department of Construction and Inspections (SDCI). Accessed 2026-08-27.
- SDCI Director's Rule 07-2025, Alteration and Repair of Unreinforced Masonry Chimneys — Seattle Department of Construction and Inspections (SDCI). Accessed 2026-08-27.