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Learn about the operation of builder's level and laser level system, proper setup and leveling procedures, measuring angles, and laying out building lines. Understand the use of leveling instruments like the David White Builder's Level and Transit. Safety precautions and care of leveling instruments are also covered.
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8 Chapter Building Layout
Objectives • Explain the operation of the builder’s level and level-transit. • Explain the basic operation of a laser level system. • Demonstrate proper setup, sighting, and leveling procedures. • Measure and lay out angles using leveling equipment. Spectra-Physics Laserplane, Inc.
Objectives (Cont.) • Read the vernier scale. • Explain the procedure of laying out building lines and finding the grade level. • Use a plumb line.
Placing Buildings • Carpenters must know where structure will be located on property • Building sites • Lots • Communities have strict requirements • Setback from street • Clearances from adjoining properties
Think Green • Organize jobsite recycling programs to minimize waste onsite • Designate places to store materials ready for reuse on jobsite • Include bins for separating wood, metal, and other scrap material for recycling
Plot Plan • Builder or owner to furnish plot plan • Location of structure • Distances to property lines on all sides • Created by surveyor • Typically shows property boundaries in feet and decimal parts of foot
Measuring Tapes • Steel tapes used for measuring and layouts involving long distances • Carpenters use tapes marked in feet and inches • Surveyors use tapes marked in feet and decimal parts of foot The Stanley Co.
Building Lines • Mark where walls of structure will be • Must conform to code requirements • Observe proper setbacks • Check clearances • Laid out as rectangle or multiple rectangles
Square Corners • Mark 6′ along one building line • Mark 8′ on intersecting building line • When distance between marks is 10′, corner is square
Laying Out with Leveling Instruments • Building lines, footings, and walls must be accurate • For small buildings, carpenter’s level and framing square are accurate enough • Larger buildings require other tools David White
Builder’s Level and Transit • Accurate for building layout • Have telescopes with accurate bubble levels • Optical device uses line of sight • Transit can determine if wall is perfectly plumb David White
Leveling Rod • Measures vertical distances from horizontal sight line • Long rod marked off with numbered graduations • Target can be moved up or down to match line of sight David White
Laser Level • Emits beam of light in 360° circle • Can be adjusted so circle is perfectly level or perfectly plumb • Functions like builder’s level to establish line Spectra-Physics Laserplane, Inc.
Safety Note • Regulations limit power output of lasers • Class II lasers limited to 1 milliwatt • Class IIIa units limited to less than 5 milliwatts • Safe for human eyes if not staring into beam Spectra-Physics Laserplane, Inc.
Care of Leveling Instruments • Keep instrument clean and dry • When removing from case, grip by base • When moving on tripod, hold instrument upright • Never overtighten leveling screws • Set tripod on firm ground • Clean lenses with camel hair brush
Using Leveling Instruments • Instruments must start from reference point • Stone marker in ground • Point on manhole cover • Instrument is located at station mark • Corner of property • Corner of building Kasten-Weiler Construction
Horizontal Graduated Circle • Divided into 1° spaces • When you rotate telescope • Graduated circle remains stationary • Vernier scale moves • When zero mark of vernier is on degree mark, reading is even degree David White
Laying Out and Staking Buildings • Done before establishing grade level • Begins with locating lot lines • Difficult to locate stakes in single operation • Temporary stakes may be used
Finding Grade Level • Grade is level of ground • Grade leveling is finding difference of grade levels among several points • Elevation refers to major levels of building • Benchmark remains undisturbed during construction
Setting Footing Stakes • First set to approximate level “by eye” • Carefully checked with rod and level • Cut and fill stakes show how much fill to adjust to reach grade level
Running Straight Lines with Transit • Used for accuracy when different elevations are involved • By pointing telescope up or down, points can be located in perfectly straight line
Vertical Planes and Lines • Transit used for: • Measuring vertical angles above or below line of sight • Plumbing building walls, columns, and posts
Total Stations • Measures horizontal and vertical angles • Also measures distances • Combines optical sensors with electronic circuitry • Can measure over any distance as long as line of sight is maintained Trimble
Construction Careers Surveyor/Surveying Technician • Establish official land boundaries and exact locations • Must meet education and experience requirements • Must pass licensing examination • Work for architectural and engineering firms and governments Celeborn/Shutterstock