What should be done about a large crack in a brick chimney?
A qualified expert – a masonry contractor, an engineer, or a registered home inspector – will have to get up close and personal with your chimney to assess its structure and stability.
Cracks in brick and stone chimneys are usually a result of damage from heat, water, ice, or a combination. Even if it’s not in use, the chimney, once compromised, will continue to degrade (and can cause more damage, or even injury, if it collapses).
If a chimney is stable and the cracking is not extensive, a contractor will install a cap made of metal or a cementitious material to fully seal the chimney’s opening. The crack will be repaired and sealed, and any weathered bricks or damaged stones will be treated with a sealant or replaced.
If the work required to stabilize the chimney is more expensive than the cost of removal, it should be dismantled. An inside chimney should probably be taken down to below roof level inside the attic, followed by roof repair. An outside chimney would be dismantled to below the area of damage and sealed with a metal or cementitious cap.
