Features of the Textbook Chapter 2 Safety 23 Pro Tip Remove nails from lumber scraps before discarding them. Failure to do so could result in injury from a puncture and lead to lost time on the job. Chapter 4, Hand Tools, shows proper tools and methods for pulling nails. Keep tools and equipment in panels or chests when they are not being used. This provides pro- tection for the tools, as well as for workers on the jobsite. In addition to improving efficiency and safety, good housekeeping helps maintain a bet- ter appearance at the construction project. This will, in turn, contribute to the good morale of all workers. Thinking Green Damaged and lost materials create unnec- essary waste on a project. Store materials in a secure location to minimize theft. Protect stored materials from damaging weather. Locate materials away from worker pathways to reduce the chance of accidental damage. Keep materials neatly organized to ensure that the materials can be located when they are needed. 2.3 Clothing Wear clothing appropriate for the work and weather conditions. Wear rain gear in wet weather, winter weight clothing in cold weather, and cool clothing in hot weather. Working when you are uncomfortable or numb from the cold detracts from your alertness and is an invitation to accidents. It is equally unsafe to work in open- toed shoes or clothing that does not protect you from the work environment. For example, shorts and short-sleeve shirts do not provide adequate protection when welding. Trousers or overalls should fit properly and have legs without cuffs. Avoid loose-fitting or ragged clothing. They can catch on nails or pull hands or other parts of the body into cutting tools or moving machinery. Keep shirts and jackets but- toned. Sleeves should also be buttoned or rolled up. All clothing should be maintained in a good state of repair and washed when dirty. Shoes should be sturdy and have thick soles to protect feet from protruding nails. Never wear shoes with leather soles such as tennis or lightweight can- vas shoes. They will not provide satisfactory trac- tion on smooth wood surfaces or on sloping roofs. When you work at a site where heavy objects can be dropped on your feet, you should wear safety shoes (covered in the next section). OSHA requires protective headgear to be worn, especially if there is work being performed overhead. Headgear should provide the necessary protection, be comfortable, permit good visibility, and shade your eyes. 2.4 Personal Protective Equipment Safety glasses are to be worn whenever work involves even the slightest potential haz- ard to your eyes, Figure 2-4. American National Standards Institute (ANSI) sets many of the stan- dards that have been adopted by industry. Safety glasses that satisfy OSHA requirements are stamped with the ANSI standard number. The specification for acceptable safety glasses is ANSI Z87.1-2003. This standard states that a safety lens must withstand the blow of a 1/8″ diameter steel ball dropped from a height of 50″. Safety boots and shoes are required on heavy construction jobs. OSHA standards Goodheart-Willcox Publisher Figure 2-3. An on-site dumpster provides safe dis- posal for construction scrap. Properly used, it will help to keep the construction site clear of debris that could cause accidents and injuries. Copyright Goodheart-Willcox Co., Inc. 200 Section 2 Foundations and Framing • Mixing time • Standing time The test is made with a sheet metal cone 4″ in diameter at the top, 8″ in diameter at the bottom, and 12″ high. 9.6.5 Giving Concrete Tensile Strength The compressive strength of concrete is high, but its tensile strength (stretching, bending, or twisting) is relatively low. For this reason, con- crete used for beams, columns, and girders must be reinforced with steel rebar. Rebar is sized by numbers 3–18. For numbers 3–8, each number rep- resents 1/8″ in diameter. So, a No. 3 rebar is 3/8″ and a No. 8 rebar is 1″. Bar sizes 9–18 do not follow the 1/8″ per number rule. They are based on the cross sectional area of the square bars that were used to form them. A number 18 bar is actually just over 2 1/4″ in diameter. These larger sizes are rarely used in building construction. No. 4 rebar may be used in a footing to prevent settling at one or more locations. When concrete must resist compression forces only, reinforcement is usually not necessary. Slabs for floors or similar applica- tions are often reinforced with welded wire fabric, Figure 9-38. The concrete can also be reinforced with high-strength fibers being added to the mix, Figure 9-39. These fibers yield nearly as much tensile strength as welded wire fabric and save time and money. Safety Note To avoid possible injury caused by a worker falling onto vertical rebar, plastic or wooden caps should be placed on the ends. An alternative is to bend the end at a 90° angle, Procedure Making a Slump Test Figure 9-37 shows the steps involved in making a slump test. 1. Secure a slump cone, wet it, and place it upright on a solid level base. The large-diameter end should be down. 2. Fill the cone with fresh concrete in three layers, each equal to about one-third of the volume of the cone. Rod (tamp) each layer 25 times before adding the next layer. See Figure 9-37A. 3. Strike off the top, then slowly and evenly remove the cone. See Figure 9-37B. This should take 5–12 seconds. Avoid jarring the mixture or tilting the cone during this step. 4. Turn the cone, small end down, and place it next to the concrete. 5. Lay the tamping rod across the top of the cone so it extends over the concrete. See Figure 9-37C. 6. Use a ruler to measure the amount of slump. Goodheart-Willcox Publisher Figure 9-35. A plastic-based material can be sprayed on concrete to form a continuous membrane that aids in proper curing. Copyright Goodheart-Willcox Co., Inc. 3 The Carpenter’s Workplace CHAPTER 1 carpenters work in commercial building construc- tion, they will likely work with metal framing materials. Increasingly, metal framing is found in residential construction. Carpenters working for general building con- tractors become involved in many different tasks. These often include laying out building lines, excavating, installing footings and foundations, framing, roofing, building stairs, drywalling, lay- ing flooring, and installing cabinets. Code Note A well-trained carpenter is expected to know the requirements of local building codes. These codes dictate where materials may be used and how a structure is to be built. Failure to follow the codes can prove costly, since inspectors may require work that does not meet code require- ments to be redone. This means more time and money spent on materials and labor. Learning Objectives After studying this chapter, you will be able to: • Cite the projected demand for carpenters in coming years. • List job possibilities for the trained carpenter. • Describe the sequence of carpentry training and apprenticeship. • Discuss abilities and characteristics needed by those in the carpentry field. • Describe the qualities employers value in an entry-level carpenter. • Describe the advantages and disadvantages of being an entrepreneur. • List other occupations that are related to carpentry. Technical Terms apprenticeship entrepreneur estimator journeyman liability manual dexterity self-employment sexual harassment SkillsUSA Carpentry is a rewarding career. It is ideal for a person who is interested in and has an aptitude for working with tools and materials, Figure 1-1. The trade requires the development of manual skills. These skills involve both thinking and doing. Carpentry also requires a thorough knowledge of the materials and methods used in construction work. Carpenters can expect to work at a variety of construction activities. They may be involved in construction of buildings, highways, bridges, docks, industrial plants, and marine structures. They cut, fit, and assemble wood and other materials. If Goodheart-Willcox Publisher Figure 1-1. Carpenters work with tools and machines. Copyright Goodheart-Willcox Co., Inc. Supplemental information and hints related to the components or procedures discussed in the chapter. Pro Tip Key items related to sustainability, energy efficiency, and environmental issues. Thinking Green Provide an overview of the chapter content and explain what should be understood on completion of the chapter. Learning Objectives List of important technical terms introduced in the chapter. The terms in this list are displayed in bold italic type when they first appear in the chapter text. Technical Terms Detailed, step-by-step instructions for accomplishing specific carpentry tasks. The procedures promote a logical, organized approach to completing common jobs. Procedures Identify situations or practices that could result in personal injury or damage if proper safety procedures are not followed. Safety Notes Call attention to requirements specified in building codes. Code Note Copyright Goodheart-Willcox Co., Inc. viii