Chimney service in Clyde Hill, WA

Houses went up on Clyde Hill from the early 1950s onward, as farmland became residential streets. We do not assume a date for any particular house, but a fireplace that has seen several owners has often been changed: an insert set into the firebox, a stove connected to the old flue, or gas logs replacing wood.

Each change raises the same question. Washington's residential code wants the lining of any masonry flue matched to the listing of whatever is connected to it, and CSIA recommends a Level 2 inspection whenever an appliance is added or swapped, or relining is planned. On the hill, that inspection is where any liner decision should start.

The Washington Department of Natural Resources gives the Puget Sound region an 85 percent chance of a deep earthquake of magnitude 6.5 or more within 50 years. The most recent big one, Nisqually, hit in 2001; afterward, researchers checked roughly 60,000 chimneys in a band running west to Bremerton and east to Mercer Island, and 1,556 had damage, clustered on the Seattle fault zone.

FEMA's advice is blunt: masonry chimneys on wood-frame houses are highly vulnerable, repointing on its own does not improve their seismic behavior, and the preferred repair after damage is a partial or full rebuild with a metal flue or insert. After any noticeable quake, CSIA recommends a Level 2 inspection before the next fire.

Being on a hill keeps Clyde Hill out of the lake's reach, not out of the rain. From October the wet season builds, and in midwinter it is common for precipitation to fall on 20 to 25 days or more a month, with humidity near 87 percent before dawn.

CSIA's position is that water, more than fire, is what wears out a masonry chimney. Its low-cost remedies are the ones we check first on the hill: a cap, a crown that overhangs the brick by about two inches, flashing that holds, and a water repellent on the brick.

Clyde Hill's mechanical permit applies to gas appliances, fireplace inserts and log lighters, as well as fans and vents, and the city issues most of them over the counter. Behind the city's rules sits the state code: Washington adopts the 2021 International Residential Code through WAC 51-51-003, and in King County the 2021 codes apply to applications deemed complete from March 15, 2024.

Washington adds its own fireplace rule in WAC 51-51-1001: a newly built masonry fireplace must have an iron or steel damper, combustion air drawn from outdoors, and doors that close tightly, or another way of controlling the draft. And FEMA notes that rebuilding a quake-damaged chimney always requires a building permit. Our quote says which of these apply to your job.