Signs Your Chimney Needs Repair
The signs that matter most: cracks or gaps at the chimney top, crumbling mortar joints, flaking (spalling) brick, rust on the cap or damper, white staining on exterior masonry, water stains on nearby ceilings, and pieces of masonry or tile appearing in the firebox. Any one of them means the system needs a professional look.
Signs visible from the ground
Walk around the chimney with binoculars or a phone camera zoom. Look for a cap that's missing, tilted or rusted; visible cracks in the crown; open or crumbling mortar joints; brick faces that are flaking off; and white powdery staining, which means water is moving through the masonry and leaving minerals behind as it evaporates.
Signs inside the house
Water stains or bubbling paint near the chimney, a damp or metallic smell from the firebox after rain, rust on the damper, and — most tellingly — debris in the firebox. Flue tile fragments or chunks of mortar falling into the firebox mean something above is deteriorating, and it won't stop on its own.
Which signs are urgent
Water-related signs are the ones that compound: every storm that finds an open crack widens the damage, and moisture repairs get more expensive the longer entry continues. Cosmetic staining can wait for a convenient appointment; active water entry and falling debris should be looked at promptly. When in doubt, describe what you're seeing over the phone — that conversation is free.