A quick overview of laser levels

Often relegated to the category of expensive measuring devices for the construction and public works professional, laser levels were previously inaccessible to most people. To have good alignment, horizontally or vertically, we still used classic level tools such as the pendulum, plumb line, chalk line or even the spirit level.

Today, laser levels are part of the tools of building professionals, but also of DIY enthusiasts. These sophisticated devices allow very precise remote plotting without having to twist or climb a ladder. Their excellent quality-price ratio has a lot to do with it, as manufacturers multiply and offer models that are functional, practical and not expensive at all.

However, if you are going to get one, it would be best if you know a little bit about a laser level or laser level device.

A tool to make alignments in all directions

Laser levels have come a long way since the appearance of the first model. The latest generation devices are generally levels rotating lasers or some automatic rotary laser levels. They allow you to project a horizontal line, a vertical line and a cross in a given volume (eg: a room) without you touching anything. Everything is fully automatic. Whether it's installing furniture, laying tiles or painting, the jobsite laser level does the work for you, freeing up one task to work on something else. You no longer have to place a spirit level and mark with a pencil and a ruler.

Some of the latest generation laser levels have other useful features such as greater laser projection angle and distance. With this type of device, you can have horizontal and vertical lines on distant walls or contiguous walls. Others are able to project a laser line 360 ??°, horizontally, which is very useful for aligning a wall frieze.

More advanced functions allow construction on inclined planes such as a staircase for example. Laser levels offer many options which are intended to make the job of a construction professional easier. These tilted laser projection features make it much easier to design a structure on slopes.

A final function, which is more for DIY professionals than amateurs, allows partitions to be made linearly, without any inclination. Plumb is an option present on most Geo Fennel lasers and makes it easy for you to align a partition, wall or pillar from floor to ceiling.

How does a laser level work?

As the name suggests, a laser level has a laser diode. The laser is an invention of the 1960s which actually stands for Light Amplification by Stimulated Emission of Radiation. It is a ray of light that contains several light waves projected continuously and coherently. On the other hand, the whole is illuminated under a beam of solid color (red laser, green laser ...) which projects towards infinity. When facing an obstacle, the laser takes the form of a point of light or a line.

In the building industry, it is used for alignment through the projection of horizontal and vertical lines. It can also be used to measure an area, especially when it is a laser rangefinder like these Leica lasers which are both range finder and laser level.

What accessories come with a laser level?

Whether it is a Bosch Laser Level, a Stanley Laser Level or one Makita Laser Level, you will always need two pieces of equipment that come with your device.


A tripod is, like an SLR camera, a support on which the laser level is placed and stabilizes. It is either delivered with the device or sold as an option for a low price. Either way, you will still need it.

Tripods usually have telescopic sliding legs that allow you to have a predicted level despite uneven topography. In the center is the central mast which, thanks to a crank, can be adjusted in height (about 160 cm)


The cane is another type of stand that can be included with the purchase or purchased separately. It remedies the problem of the tripod which cannot be wedged between the floor and the ceiling. Indeed, the rod is placed vertically and allows you to move your laser level up and down.

What are the key points to remember when using a laser level?


The accuracy of a marking with a laser level depends on the fineness and above all the visibility of the line projected by the device. This is because no horizontal or vertical line can be drawn correctly if you cannot see anything in it. To work efficiently, consider darkening the room where you will be working. In a room with openings, close the curtains. Alternatively, you can also wear laser vision glasses which allows you to distinguish the line despite the high brightness.


On the automatic laser levels, automatic leveling allows you to work faster. They are equipped with a pendulum which makes it possible to obtain an automatic level on a horizontal plane in a few seconds on a ground with a slope ranging from 3 to 5 °. An indicator light alerts you that the laser level is perfectly level and you can begin your alignment work.


Stability is provided by the tripod or cane with metal spikes which must be driven into the ground or soft material to prevent the laser level from moving at the slightest rotation.

What are the precautions for using a laser level?

Laser levels use a professional laser which can have different classes depending on the model and which can present eye and even skin risks. Like any number graduation, the lower the number, the more harmless the laser. But, the class of laser levels starts from Class 2 or 2M which produces a power of 1 mW or 2 mW for some models of Bosch Rotary Laser. If you receive a beam directly into the eye for more than 250 milliseconds, you will damage the eye with momentary blindness.

Class 3A or 3R lasers have a power of 5 mW and the risks to the eyes are the same as with a Class 2 laser. From Class 4 lasers it is important to protect both the eyes and the eyes. the skin.

Also, a laser level for indoor use cannot be used outdoors. For outdoor work, it is always advisable to use the Outdoor Laser Level that suits you. With a suitable model, you run no risk of damaging the device in the event of rain.