A chimney pulling away from the house
A gap opening between an exterior chimney and the house wall means the stack is moving independently. The cause may be settlement of the chimney's footing, failed ties to the house, or past shaking. It is a structural issue, not a cosmetic one.
Until it has been looked at, the fireplace should not be used; Earthquake Country Alliance's advice is not to use a fireplace with a damaged chimney. Repair may involve new anchors to the framing, work on the footing, or rebuilding the part that has moved.
Chimney pots, corbelling and decorative tops
Where a San Marino house was built in a period-revival style, its chimney may carry decorative brickwork: corbelled courses that step out near the top, patterned brick, or clay chimney pots on the flues. Those details are the first to lose mortar, because they stick out into the weather.
A loose chimney pot is a falling hazard and should be secured or removed promptly. Repairing corbelling means relaying the stepped courses to their original projections, which takes measuring before anything comes down.
Tell us how tall the chimney is relative to the roof, whether it is brick, stucco or stone, and what has changed. Call or send the details, and ask for an estimate for the work.
When stucco or stone hides the brick
Where a chimney is clad in stucco or stone veneer, the structural brick is out of sight. Cracks in the cladding may be surface movement or may follow a crack in the masonry beneath.
Telling which sometimes means opening a section of cladding. That is worth agreeing in advance, along with how the opening will be closed to match.
Repair now, rebuild the top, or reduce the stack
Sound brick with failed joints or a cracked crown is repaired in place. Loose top courses are taken down and relaid. A stack that is cracked through or has moved is a rebuild question.
A rebuilt chimney must meet the California Residential Code: at least 3 feet above where it passes through the roof and at least 2 feet higher than any part of a building within 10 feet. Where the fireplace is no longer used, some owners consider reducing the stack and capping it. Permits, and whether any design review applies, are for the City of San Marino to decide.
Cost factors on a large San Marino chimney
Height, and whether scaffolding is needed, usually leads. Then come the number of flues in the stack, the amount of decorative detail to rebuild, matching brick, whether cladding has to be opened, bracing or anchoring hardware, and protecting the roof covering around the work.