How to Use a Laser Level for Perfectly Straight Lines

A level is a simple tool used in a wide range of industries to check whether a surface is level or plumb. Level refers to a horizontal surface that is completely flat and sits at 0 degrees, while plumb is the term used for a vertical surface that is erected at 90 degrees. Using a traditional level helps ensure building projects remain straight and stable, but this can be a time-consuming endeavor.

Instead, you can invest in a laser level, which emits a red or green laser in a straight line, making it easier to lay tile, mount cabinets, or put in framework. There are several types of laser levels available, depending on the job. You can even find self-leveling laser levels that take some of the guesswork out of setting up the level. Use this guide to learn more about laser levels and how to use a laser level for your next home renovation project.

What Is a Laser Level?

While you might opt for a traditional analog level for some home projects, there are some jobs where a laser level can save you hours of time.

A laser level is a device that emits a visible green or red laser in a completely straight line. The laser level still needs to be manually adjusted with each use to properly display level or plumb, unless you invest in a self-leveling laser level. A self-leveling laser level uses a pendulum system and an internal magnet to ensure a level reading. DIYers and construction experts can then use this visible laser line to ensure that their projects remain level and plumb as they work. While this might be unnecessary for checking something simple, like if a TV mount is level or not, a laser level is highly effective for larger projects, like tiling a shower or putting in a new floor.

Types of Laser Levels

There are three main types of laser levels to choose from for your home projects, including rotary, dot/plumb, and line laser levels.

Rotary Laser Levels

A rotary laser level emits a 360-degree laser beam at a high speed, creating a visible plane of red or green light, instead of a simple line like other types of laser levels. This type of level is highly effective for constructing walls, establishing a foundation, and creating slopes on driveways or docks. Rotary laser levels are typically accurate to within 1/16th of an inch up to 50 feet, or within 1/8th of an inch up to 100 feet, making them ideal for professional construction projects.

However, this device comes at a high price that is more understandable for a professional contractor or construction company. Most DIYers will not get enough use out of a rotary laser level to justify the cost of this innovative tool.

Dot/Plumb Laser Levels

A more affordable alternative to a rotary laser level is the dot/plumb laser level, which projects two, three, or five beams of light to create a line of dots on a surface. These projected beams can be used to indicate level, plumb, and 90-degree angles, with highly visible red or green light beams that intersect on the target surface. While you can turn on or off the beams as needed, keep in mind that dot/plumb laser levels are only accurate to within 1/4th of an inch up to 100 feet.

Line Laser Levels

Another great choice for DIYers is the line laser level. This tool is the most common type of laser level and is typically used for indoor projects. It's generally accurate to within 1/4th of an inch up to 100 feet, though this may differ between products.

Line laser levels emit a horizontal or vertical red or green laser line onto the target surface to indicate level or plumb. Most line laser levels can pivot 180 degrees, though there are some advanced line laser levels that can pivot a full 360 degrees. This type of laser level is affordable, easy to use, and effective for a wide range of home renovation projects.

How to Use a Laser Level

Learning how to use a laser level is relatively straightforward, though there are differences between products, so it's important to refer to the manufacturer's directions for use.

Start by setting up the laser level on a flat surface or a tripod to ensure that it won't shift during use. If your laser level doesn't have self-leveling functionality, you'll need to manually adjust the device using the bubble vial on the side of the level.

A laser level with self-leveling functionality will adjust itself after you turn on the device, so make sure to give it a few minutes when you first turn it on. The laser level will emit a line, beam, or plane of light, depending on the type of level you're using. Find the current location of the laser light and check the accuracy of the tool against a traditional rotary level.

At this point, you can use the projected light for a variety of projects. Mark level on the wall for hanging pictures, use the light as an indicator for building framework, or use the laser level to ensure new cabinet hardware is level and plumb on each door.

Buying Vs. Renting a Laser Level

Not every home renovation project requires a laser level, so if you plan to use this tool once or twice throughout the year, it might be more cost-effective to rent a laser level from a local home improvement store. Small line or dot/plumb laser levels are typically an affordable investment for the home workshop, but if you need a rotary laser level, it's recommended to rent this costly tool.

Rotary laser levels are more appropriate for contractors and construction professionals who use this device enough to make the high cost worth the investment. DIYers can use a rotary level, but the average homeowner isn't likely to find enough uses to justify the purchase.

Laser Level Maintenance

When you purchase a laser level, it should be ready to use with very little setup. However, to keep the laser level working properly, it's important to take care of this delicate tool when it's not in use. If your laser level doesn't come with a case, consider purchasing a case to protect your investment in this helpful tool. Additionally, it's recommended to test the accuracy of the laser level against a standard analog level or a plumb line about once every three to four months.

This simple test ensures the laser level presents accurate information, so that you don't get halfway through a project and realize it's slightly slanted. If your laser level can be calibrated, follow the directions provided by the manufacturer to calibrate it if you notice it is no longer accurate. However, if the level can't be calibrated, you may need to replace the device.

It's also a good idea to remove the batteries from the laser level before storing it. Otherwise, there is a chance the batteries could corrode within the laser level and cause damage to the interior of the device.