Chimney Crown Repair & Rebuild Seattle, WA

The chimney crown is the sloped slab of concrete or mortar that covers the top of a masonry chimney and sheds water away from the bricks and flue. It is not the metal cap that sits over the flue opening; the crown is the masonry surface the cap is mounted on. When the crown cracks, crumbles or loses its slope, rain runs straight into the chimney structure, and that is where most of the expensive masonry damage we see in the Seattle area begins.

James Chimney Sweep repairs and rebuilds chimney crowns for homeowners in King, Pierce and Snohomish counties. If your crown is structurally sound with surface cracking, a flexible crown coat or sealant repair restores the waterproof surface. If the slab is broken, thin, flat or separating from the chimney, the crown is rebuilt or re-poured so the chimney gets a proper overhang and slope. A technician starts by confirming which situation you actually have, because the wrong fix on a failed crown is money wasted.

Crown problems are common on older Seattle homes because many original crowns were simply a thin smear of mortar troweled over the last course of brick. That style of crown was never designed to survive decades of Pacific Northwest rain and winter freeze-thaw cycles.

Timing & Safety

When Crown Repair Is Necessary vs. Optional

Necessary now:

• The crown is cracked through, missing pieces or separating from the chimney.
• There is evidence water is getting into the chimney: spalling brick, interior stains, a damp firebox, rust on the damper.
• The flue tile is loose or cracked at the top, which usually means water has been freezing in the crown.
• An inspection found crown deterioration and recommended repair.

Worth doing soon (preventive):

• Hairline surface cracks on an otherwise good crown. Sealing now is far cheaper than rebuilding later.
• A crown with no coating that is more than a few years old, especially on the wet side of the house.
• You are already having the cap, flashing or upper masonry worked on; adding a crown coat while a technician is on the roof is efficient.

Optional: a freshly poured crown that is properly sloped, overhangs the brick and shows no cracks can simply be monitored at your annual inspection. NFPA 211 recommends a chimney inspection every year, and the crown is one of the items that inspection covers.

Safety considerations

Crown work happens at the highest point of the house, often on a steep, wet roof. Please leave the climbing to our team; do not go on the roof to inspect or patch the crown yourself, and do not lean a ladder against the chimney, because deteriorated masonry can give way. Ground-level binoculars are the safe way to spot obvious crown damage from your yard.

• Falling crown pieces are a hazard to people, pets and cars below; if you see chunks in the gutters or on the roof, keep the area clear and request an inspection.
• A failed crown lets water reach the flue liner. Cracked liner tiles can allow heat and combustion gases to reach framing, so a damaged crown is not just a cosmetic issue.
• If water has reached the firebox or damper, stop using the fireplace until the chimney has been inspected.
• If your fireplace or insert runs on gas and you ever smell gas, leave the house and call your gas utility or 911 from outside.

Seattle & Puget Sound conditions

Seattle and the Puget Sound get most of their rain between October and April, and the chimney crown is the one surface on the house that faces straight up into it for months at a time. Moss takes hold in hairline cracks and holds moisture against the concrete, and the wet-then-freezing nights we get in December and January push that water into ice, widening every crack a little more each year. By spring, a crown that looked fine in September can be shedding pieces. This is also why a thin, flat mortar crown that may have survived in a drier climate fails early here. We schedule coatings and re-pours during dry stretches so the material cures properly, which usually means late spring through early fall is the ideal window, though short dry windows in other seasons can work for small repairs.