Note type of material used for chimney such as brick, block, metal and type of flue if visible such as clay lined or flexible metal. When inspecting the chimney, note missing or broken bricks or stones, missing or damaged chimney caps and flashing, proper damper operation and any signs of moisture damage. If clean out door is accessible, check for soot, debris, nests or signs of wild animal penetration. Use Thermal Imager as necessary to detect moisture issues.