How do I know if my chimney needs repair?

Common signs a chimney needs masonry repair are crumbling or missing mortar joints, spalling or flaking bricks, a cracked crown, white efflorescence staining, rust on the damper, water stains on ceilings near the chimney, and any visible lean. • Mortar you can scratch out with a screwdriver • Brick faces flaking, popping or shedding grit • Cracked or missing chimney crown or cap • Water stains on the ceiling or in the firebox • Loose or rusted flashing where the chimney meets the roof