Demolition and renovation work present unique hazards that, unfortunately, often are overlooked and result in job-related injuries and fatalities. These dangers can be controlled and eliminated with the appropriate planning, proper personal protective equipment (PPE), effective safety training and compliance with OSHA regulations.
Safety risks from demolition work can come from structural or design changes and modifications or alterations to the original design. The work also may result in exposure to lead, silica, asbestos and other chemicals.
Prior to beginning demolition work, preparation is key. The overall planning process should include how the structure is going to be brought down, what equipment is needed and how to perform the work safely. Before starting, complete a written engineering survey for each structure being leveled. This will help identify the condition of the framing, floors and walls and to assess the possibility of unplanned collapsing. Walls and floors that have been damaged should be braced. All stairs, passageways and ladders should be properly lit and inspected prior to worker entry. Additionally, all employees should be outfitted with the appropriate PPE.
Before initiating demolition work, notify utility companies and ensure electric, gas, water, steam, sewer and other service lines outside the structure are capped and/or shut off. If necessary, utilities can be temporarily relocated to protect any essential power, water or other services. The appropriate personnel should also identify hazardous chemicals, gases, explosives and flammable materials in any pipes, tanks or other equipment on the property.
Once demolition begins, debris should be removed while circumventing falling hazards. Floor openings should be covered and secured.
According to OSHA’s Demolition and Cleanup Fact Sheet: “Debris dropped through holes in the floor without the use of chutes must be completely enclosed with barricades ... . Use enclosed chutes with gates on the discharge end to drop material to the ground. Design and construct chutes that will withstand the loads likely to be imposed without failing.” Additionally, posted signs must be used to warn individuals of falling hazards. Protect entrances to multistory structures with sidewalk sheds or canopies.
When removing walls and masonry sections of exterior walls and floors, the fact sheet states, “Begin at the top of the structure and proceed downward. Masonry walls must not be permitted to fall on the floors of a building in masses that would exceed the safe carrying capacities of the floors. No wall section, one story in height or higher, shall be permitted to stand alone without lateral bracing, unless such a wall was originally designed and constructed to stand without such lateral support, and is safe enough to be self-supporting. All walls must be left in a stable condition at the end of each work shift. Employees shall not work on the top of a wall when weather conditions create a hazard.”
After demolition and cleanup is complete, renovation is frequently necessary. Most renovation projects require the use of temporary power. However, this also presents hazards, including the risk of shock, electrocution and fire. Typically, electrical contractors are responsible for establishing and maintaining power, as well as creating a safe environment. This responsibility includes coordinating with the general contractor and/or host on any special conditions or requirements they may have.
When working with temporary power, installation, consider use and maintenance. NECA’s NFPA 70E “Guide to Policies and Best Practices” states: “Temporary wiring should be designed and installed according to OSHA, NEC and NFPA 70E requirements. Only qualified and authorized persons should design, install and maintain temporary wiring systems for any job site or location. Temporary wiring should be adequate for the load and environment it will be exposed to. All temporary wiring should be removed as soon as the need for temporary power is over.” For portable generators, the guide states workers should follow all manufacturer requirements to provide portable/temporary power including maintenance and refueling activities.
To protect others, use warning signs for temporary wiring and devices. Improperly marked cables can result in serious hazards to unaware workers. Access should also be limited to authorized personnel only. When not in use, ensure doors and covers are locked. If any extension cords are exposed to the elements or wet conditions the consequences can be catastrophic.
Hopefully, this information has helped make you more familiar with the hazards associated with demolition and renovation work, as well as how to navigate them safely.