Lasers are not new to construction applications. Conventional surveying tools years ago gave way to lasers for accurately preparing contours of land on building sites in preparation for construction and for planning routes for city streets, new subdivisions and interstate highways.
Simple, inexpensive laser distance-measuring devices are available in every hardware and home-improvement store at prices any homeowner or do-it-yourselfer can afford. Electricians and other tradesmen use more sophisticated and durable laser measuring and leveling devices.
For large commercial and industrial projects, many electrical, mechanical and plumbing contractors consider laser layout equipment a necessity. Time is money, and there simply is no way string lines and plumb bobs can lay out locations of a large commercial project’s cable runs, cable tray hangers, ducts, lighting fixtures, floor and wall penetrations for outlets, breaker boxes, and other components as quickly and accurately as laser layout systems can.
Every project is different
Jarrod Krug, marketing communications manager for Trimble Building Construction (www.trimble.com/construction/building-construction), said it is difficult to generalize the amount of time saved by using laser layout systems because every project is different.
“However,” he said, “most electrical, mechanical and plumbing contractors tell us they are seeing roughly a one-and-a-half to two times increase in productivity on complex projects with compressed schedules. Using a laser layout system with direct office-to-field functionality, one person can accurately layout hundreds of points in a single work day.”
Mike Tramontin, executive vice president of Pacific Laser Systems (PLS) (www.plslaser.com), said his company estimates that as much as 25 percent of a contractor’s workload is layout and that a laser system can save up to 50 percent in time and improve accuracy. PLS markets handheld, self-leveling, laser layout and alignment tools.
Trimble’s robotic construction layout station is theodolite integrated with an electronic distance meter to read distances from the instrument to a specific point and software that allows the addition of field points with XYZ coordinates to a CAD file, which can be exported to the robotic station for location and stake out.
“We are seeing electrical contractors use the technology to mark the locations of fire boxes and electrical panels with circuit numbers as well as security info prior to concrete pour,” Krug said. “They are marking the locations on the floor and then applying a layer of clear coat to maintain the markings against the elements.”
The benefits of laser layout systems extend beyond simply laying out a project, Krug said.
“As owners and general contractors start to embrace integrated project delivery [IPD] oriented contracts, the need for all aspects of a building construction project to adhere to tighter and structured scheduling parameters is driving the adoption of laser-based layout tied to the design data flow, including work of electrical, mechanical and plumbing subcontractors. Compared to the design/build project delivery method, which places the contractor in the leading role on a building project, IPD involves the entire building team including the owner, architect, general contractor, building engineers, fabricators and subcontractors working collaboratively throughout the construction process,” Krug said.
In addition, laser layout systems can provide as-built records to the general contractor for quality assurance and risk mitigation.
Krug said refining conventional land survey equipment to the more vertically oriented applications for working in buildings has resulted in development of specific features and capabilities for these applications. Examples include staking out points in indoor situations and using direct reflection layout technology to visually reference where the laser is pointing, which helps save time while increasing overall accuracy.
“Additionally,” Krug said, “we have added a full-featured Microsoft Windows 7 tablet-based solution to the construction layout portfolio, providing the optimum canvas for the Trimble Field Link layout software offering a simplified, touchscreen-based user interface with intuitive vertical construction specific workflows.”
The most critical step in making layouts is establishing control points, Krug said.
“Nothing can cure the wrong control,” he said. “If the project control points are off, then the laser based robotic layout point locations will be off. Having the survey control points correctly staked at the beginning of a project is key to experiencing the true value of laser-based construction layout technology.”
PLS’s Tramontin said laser layout equipment has steadily evolved.
“Most tools’ evolution in the last three years have combined layout points and layout lines into one tool,” he said. “Tools continue to be married with useful accessories that are ideal for electricians and other trades. Battery and diode life is longer. Warranties on some products have been extended from one year to three years.”
When evaluating laser layout tools, Tramontin said a buyer’s first consideration should be how the tools should be used and what will be expected of them. Next, evaluate accuracy, brightness, portability, warranty, where it’s made or assembled, and, finally, price for the quality of the information generated.
Tramontin believes it has become rare and even questionable for professional electricians not to use laser layout tools on projects; they significantly reduce labor and errors.
“The option is staying with traditional labor-intensive methods,” he said. “Electricians who do residential work may be able to use old methods; however, residences with high, vaulted or cathedral ceilings and high-end remodeling jobs justify the use of lasers for layouts.”
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at email@example.com.