Crowns that were never built as crowns
Some older chimneys finish with a thin wash of mortar sloped off the top bricks rather than a formed crown. The current California Residential Code (R1003.9.1) calls for a concrete, metal or stone cap with a drip edge and a caulked bond break around the flue liner. A mortar wash has none of those, cracks readily and lets water into the stack.
Sealing a crack buys time on a crown that is otherwise sound. A crumbling wash is replaced with a formed crown that overhangs the brick so water drips clear.
Cracked, shifted or missing flue tile
Clay tile liners crack from sudden heat, chimney fires and ground movement, and some older chimneys were built with no liner at all. Either way, the flue no longer keeps heat and gases where they belong, and they can reach the brick and nearby framing.
A cracked tile is found with a camera, not from the firebox. The fix may be replacing sections, or relining with stainless steel or a cast-in-place liner, depending on how much is damaged and what the flue serves.
Describe what you can see from the ground, and whether the chimney has been worked on since the house was built. Describe the problem and request an estimate.
Tall brick stacks, earthquakes and bracing
Earthquake Country Alliance says all masonry should be reinforced and names inadequately braced chimneys as a common problem. On an unreinforced brick chimney, the section above the roofline is the most exposed in shaking, and options run from steel bracing to rebuilding that section with reinforcement.
The City of Arcadia decides what approvals structural chimney work needs.
A stack leaning away from the house, a crack running through several courses, or loose bricks near the outlet are reasons to act. Until it has been checked, keep people clear of its base and leave the fireplace unlit.
Repair the upper stack or rebuild it
When the upper courses are loose, the crown has failed and the joints below are open, the total can amount to rebuilding from the roofline up. That is often the point at which reinforcement is added.
A rebuild is not automatic. If the brick is sound and the damage is limited to joints and crown, repointing and a new crown keep the original stack in place.
What an Arcadia masonry repair estimate depends on
Masonry pricing follows the extent of the damage and how hard it is to reach.
- 1How many joints need repointing, and whether mortar has to be matched.
- 2Crown repair or a new formed crown.
- 3The relining method, if the flue tile has failed.
- 4Chimney height, roof covering and whether scaffolding is needed.
- 5Bracing or partial rebuild, and the approvals that go with it.