Like most plant components industrial chimneys are subject to deterioration with use or time. Chimneys may also be damaged by misuse, changes in operating conditions or from process faults. The consequences of unscheduled outages or failures can be very costly. For these reasons chimney inspections should be carried out systematically and regularly, and not left until the damage becomes apparent or the chimney becomes unsafe. Repair and maintenance is an essential part of extending the life of the chimney structure.