“Close” is not good enough on today’s jobsites. Close is not good enough on today’s jobsites. Contractors must be right-on with every control mark. Workers must comply with project specifications that include tight construction tolerances, leaving no room for onsite corrections. One control marking error can cost severe penalties and hours of unnecessary work and delays. Fortunately, there’s a way to provide workers with clear, accurate field markings that speed up jobs, eliminate errors, and aid in contractor profitability. Contractors have turned to laser levels for the precision they need on project layouts to achieve these advantages. These instruments use laser beam projectors to provide one or more fixed lines or dots along the horizontal and/or vertical axis. These clear strong control beams help craftsmen align their work even on the toughest job site conditions. Where Are Laser Levels Used? Laser levels are swiftly replacing plumb bobs and hand levels as the tool of choice for accurate layouts on both enclosed areas and outdoor projects for every craft. Laser levels are used for leveling and aligning vertical, horizontal, square, angle, grading-slope and point-transferring applications. They are first used to align framing, walls, and ceilings. Then finishing crews can establish their own control points without leaving any permanent marks. This includes floor and drop ceiling installations, window and door height checks, and fine carpentry such as chair rails, cabinets, and trim. Laser levels also permeate outdoor construction site layout. Contractors easily grade stakes, alignment, and masonry level posts. Flat work contractors use target beams to establish top surface elevations and laser screed alignment. Landscapers use these devices for various leveling projects like terracing and retaining walls. Durable Tools Laser levels have evolved from delicate, complicated instruments into sturdy tools that are easy to set up and use. In general terms laser levels are classified as one of three types: Dot, Line and Rotary. These are determined by the way the instruments emit their projections. DOT (or “POINT”) LASERS Dot lasers project a single or multiple reference points on work surfaces. Contractors primarily use these lasers to layout vertical reference points, as they would with a plumb bob. Great for most plumbing, alignment and leveling tasks. These tools are very useful when marking ceilings and walls. Most models project either 3 points or 5 points. LINE LASERS AND CROSS-LINE LASERS Line Laser Levels project a beam in a level line in one direction along a single work surface. These types of lasers are typically used indoors on a single wall. Some units emit cross-hair projections and many are self-leveling. Line laser units are either handheld or mounted on a lightweight platform such as ladder or jamb-pole. Generally, line and dot lasers are used for distances under 150 feet. ROTARY LASERS Rotary lasers spin on a vertical axis to emit a projection that looks like a level line around the work area in 360 degrees. Some rotary laser level models can be laid over on their side, using an optional trivet to project on a vertical plane. These lasers are typically larger than line and dot lasers and are usually mounted on surveying tripods. When used inside, workers can easily see the line projection. When used outside, workers find their marks with a laser receiver. Rotary lasers can be used to place marks that are used for distances exceeding 200 feet. Projection Types Laser levels typically emit their projections in two ways. A horizontal beam laser will only emit a single beam from its beacon. Dual-beam lasers emit horizontal or vertical beams to establish both level and plumb reference lines. The term of “Dual-Beam” means that the laser is able to produce its regular plane and produce an additional reference point such as a plumb-up dot on the ceiling. Most Rotary Lasers are either horizontal, or vertical, (one or the other, not both). Dual-Beam is just another beam, not necessarily another “plane”, as the second beam could be a simple “dot” reference point. Laser Levels Are Easy To Use It’s safe to say laser levels are easy to set up, especially if you get a newer model with the latest options, Generating accurate markings are so easy you’ll wonder how you got by so long without one. Basic models are usually manual leveling lasers, requiring the operator to level the unit by turning thumbs screws while referencing the instrument’s bubble vials. To save time, many contractors are turning to self-leveling lasers. The terms “self leveling” and “automatic leveling” are not interchangeable. Most self-leveling lasers have an internal pendulum that does the leveling. Automatic-Leveling Lasers have electronic servo motors that do all of the leveling for you. The instrument automatically finds and maintains a level within a specified range. The basic self- leveling lasers require the operators to first perform rough leveling and then the laser itself will take over and do the fine leveling. More advanced auto-leveling lasers continue to self-correct even when your setup or platform becomes jarred accidentally. And if the sensor determines you are severely out of level, it will shut down. Choosing Rotation Speeds For Your Rotary Laser Contractors have some options when selecting a rotary laser level rotation speed. The choices are either a fixed rotation speed, or a variable rotation speed. A faster RPM is dimmer but travels farther. Conversely, a slower RPM does not travel as far but is brighter and easier to see. Rotary laser levels equipped with variable rotational speeds allowing workers to adjust the laser to the speed of best visibility. Slower rotations have a more visible beam. Faster rotations resemble a chalk line. Contractors can find the best mix of solid and brightness for projections by setting the rotation speed just fast enough so it emits a solid line on the wall. When there’s the need for a steady, solid dot for a mark, operators can set the laser’s speed at 0 RPM. When doing exterior work (outside jobs such as grading, setting culverts, concrete driveways) you need one speed, and that speed is fast. The line from a rotary laser is not visible to the human eye outdoors in bright sunlight, so you will need to use a laser detector to find the exact location of the laser line. The faster the rotation, the harder it is for a human eye to see it, but laser detectors work better with faster rotations – set to at least 600 RPM. Using A Laser Detector (AKA: Laser Receiver) Contractors use a laser detector to check elevations and to set control points. These are useful tools when working outside with a laser level as the projection is difficult to see during the daytime hours. Detectors are equipped with visual and audible indicators that alert the worker on its position with respect to the laser beam. While visual indications appear on an LCD screen, most workers prefer the audible indicator. The detector emits a series of tones in increasingly rapid succession as you approach the beam. The tone stays solid when you are on level. There are two additional methods to see the laser level beams in the field. Beam-Finders and Laser Targets are passive accessories that enhance the visibility of the laser beam. Beam-Finders are special glasses that help you see the beam. Glasses must be matched to the beam’s color. Another method is to place Laser Targets to reflect the projection beam. Targets can be placed on a surface or hung using a built-in magnet. Seeing Red or Green? In recent years laser level manufacturers have been offering instruments with green projections. The new technology allows these laser levels to be only slightly more expensive than a comparable device with a red beam depending on make and model. Contractors should consider their jobsite conditions when choosing whether they should select a laser level that projects red or green laser lines. In many cases, both the red and green beam lasers will do the job, but there are instances where the green beam offers advantages. That includes applications requiring greater distances and jobs where ambient light is a consideration. For the most part, green beam lasers can do everything a red laser can, plus they allow contractors to handle any task on the jobsite, regardless of ambient light pollution. Green beam lasers are best for applications with bright light conditions, like framing a house, placing a foundation or slab where there aren’t any walls blocking direct sunlight. The visibility of a green laser may increase the level’s range by up to 50 percent, even traveling up to three miles, which is why green is essential in various industrial worksites. Remember, when using a green laser level, you must also use a green laser detector. .