Proper material handling is an essential element of a well-run roofing project. Failing to plan for lifts, using worn or defective slings, and exceeding the capacity of lifting equipment are just a few examples of material handling issues than can result in damaged property or inventory, lost productivity and injury.
Occupational Safety and Health Administration (OSHA) construction standard Subpart H, 29 CFR 1926.250-252, contains rules for material handling, storage, use and disposal on a job site. It includes a variety of requirements regarding trash chutes, housekeeping, wire rope, chains and synthetic slings.
Take out the trash
Trash disposal from a roof can be handled in various ways, including placing trash in a skid box, on pallets or in other suitable containers and lowering it to the ground with a crane or forklift. However, when trash is dropped more than 20 feet to a point outside a building's exterior walls, OSHA requires the use of a chute, which it defines as a slide that is enclosed on all sides.
Many roofing contractors will tell you an organized job site is an efficient job site, and OSHA rules give that axiom the force of law. OSHA construction standards demand that storage areas be kept clear of material accumulations constituting a trip hazard, fire hazard or explosion hazard. All scrap lumber, waste material and trash must be removed from a work area as work progresses and not left until the end of the day or week. In addition, all solvent waste, oily rags and flammable liquids, such as those used to clean tools, must be kept in fire-resistant covered containers until they are removed from a job site.
Rigging loads to be lifted by a crane or hoist presents some challenges in terms of equipment to use and procedures to follow. At the start of a shift, crew members should inspect rigging equipment, such as slings, chains or ropes, to be certain they are safe and free of any defects. Additional inspections must be conducted while the equipment is in use to ensure it is safe. Any defective equipment must be removed from service.
A worker rigging a load must be aware of the weight capacity or limit set by the manufacturer of the particular sling, chain or rope being used. A synthetic sling usually will have its load capacity marked on one of the strap ends near the loop. It is useful to keep that marked capacity free of dirt or other material that could obscure it.
Workers should inspect natural or synthetic rope used in rigging loads for:
Workers should check synthetic webbing used in rigging loads for:
Some manufacturers place a colored fiber (usually red) inside some ropes and webbings of synthetic slings to act as a more obvious wear indicator. "If you see red, you're dead" is a saying used to remind workers of the significance of the observations they make during an inspection of this type of rigging equipment.
Knots in slings and ropes must be avoided at all times because load forces concentrate at the knotted portion, making it susceptible to failure. For the same reason, slings never should be shortened with bolts, clamps or other makeshift devices. Slings must be padded or protected in some way from sharp edges of a load that could cut or abrade the sling.
A worker rigging a load must never place his fingers or hands between a sling or rope and the load being lifted. OSHA rules also prohibit shock loading—sudden impact of a load caused by a rapid change of movement, such as swinging or falling, which is transmitted to the sling, rope or cable lifting the load. For example, a load that is dragged from a roof surface by a crane and then free falls after going over the roof's edge before stabilizing would shock load the rigging and lift lines.
Knowledge of applicable OSHA rules and an understanding of the hazards related to rigging equipment will benefit your workers. Inspecting rigging equipment at the start of a shift and as work progresses will keep workers safe and inventory and property at job sites undamaged.
Harry Dietz is NRCA's director of safety and regulatory compliance.