Chimneys should be cleaned annually – and/or after every 36 lit fires in the fireplace. Chimneys should also be cleaned if any soot is seen inside your home, after a pre-built home is purchased, BEFORE a new home is purchased, and before every Winter season. Furthermore, chimneys must be cleaned after a fire in your home or the chimney, if any stains appear in or around the chimney, after any roof replacement, or in the event of a lightning strike or falling tree impact.