For the purpose of the Washington state public works law, chapter 39.12 RCW, sheet metal workers perform the following work:

(1) The handling, conditioning, assembling, installing, servicing, repairing, altering and dismantling of the duct work for the heating, ventilation and air conditioning systems regardless of the materials used and the setting and the servicing of all equipment and all supports and reinforcements in connection therewith.

(2) The installation of expansion and discharge valves, air filters, and water filters in heating, ventilation and air conditioning systems.

(3) The testing and balancing of air-handling equipment and duct work.

(4) The handling, conditioning, assembling, installing, repairing and dismantling (except when a building is demolished) of cornices, gutters and down spouts.

(5) The installation of metal siding and metal roof decking, regardless of the fastening method, or what it is fastened to.

(6) The installation of furnaces and any and all sheet metal work in connection with or incidental to commercial kitchen equipment or refrigerating plants.

(7) The handling, moving, hoisting and storing of all sheet metal materials on the job site and all the cleanup required in connection with sheet metal work.