30 Section 1 Preparing to Build Safety Note Always wear safety glasses when working with pneumatic tools or any compressed gas. Never direct an air stream at yourself or another person. Do not use compressed air to blow dust off your skin or clothes. Pneumatic tools should be equipped with quick discon- nect fittings, Figure 2-14. 2.11 Decks and Floors To perform an operation safely, either with hand or power tools, the carpenter should stand on a firm, solid base. The surface should be smooth, but not slippery. Do not attempt to work over rough piles of earth or on stacks of material that are unstable. Whenever possible, stay well away from floor openings, floor edges, and exca- vations. Where this cannot be done, install ade- quate guardrails or barricades. In cold weather, remove ice from work surfaces. 2.12 Excavations Shoring and adequate bracing must be placed across the face of any excavation where the ground is cracked or a cave-in is likely to occur. Shoring is braces and blocks used to support a heavy load (the face of the excavation in this case). Inspect the excavation and shoring daily, especially after rain. Follow state and local regulations. Never climb into an open trench until proper reinforce- ment against cave-in has been installed or until the sides have been sloped to the angle of repose of the material being excavated. Angle of repose is the angle the soil naturally assumes when it is unsupported. A few days before beginning any excavation, call 811 and tell the operator where you plan to dig. The 811 operator will notify the utility com- panies in the area and within a couple of days they will come to your site and mark any buried utilities. 811 is operational just about everywhere, but if you work in an area where it is not avail- able, check with the local utility companies before you dig. Excavated soil and rock must be stored at least 1′ away from the edge of an excavation for every foot the pile is high. Use ladders or steps to enter trenches that are more than 4′ deep. OSHA defines a trench as an excavation that is deeper than it is wide and is less than 15′ wide at the bottom. In the United States, an average of two workers per month are killed as a result of trenches collapsing on them. Trenches 5′ deep or greater require a protective system unless the excavation is made entirely in stable rock. A pro- tective system may consist of shoring or a device called a trench box. A trench box is a steel box, inside of which work can be performed in safety. A protective system may be needed for trenches less than 5′ deep. 2.13 Falling Objects When working on upper levels of a structure, be cautious handling tools and materials so that there is no chance of them falling on workers below. Do not place tools on the edge of scaffolds, stepladders, windowsills, or on any other surface where they might be knocked off. If long pieces of lumber must be leaned against the side of the structure, position them on enough of an angle so that they will not fall sideways. When moving through a building under con- struction, be aware of overhead work, and, wher- ever possible, avoid passing directly beneath other workers. Stay clear of materials being hoisted. Wear an approved hard hat whenever there is a possibility of falling objects. Falling objects are one type of “struck-by” hazard. Other examples of struck-by hazards include vehicles being driven on a jobsite, loads being lifted and moved by cranes, walls under construction that may fail, and stored materials that are not properly secured. Goodheart-Willcox Publisher Figure 2-14. Pneumatic tools should always be equipped with a quick-disconnect coupling. Copyright Goodheart-Willcox Co., Inc.