Levels are essential to virtually every carpentry project. They help you build walls that are perfectly vertical (plumb), shelves, countertops, steps that are level, and roofs that incline at a correct and consistent pitch.
Take care of your levels. Unlike some other tools that can be tossed into a tool bucket without damage, a level is a finely tuned instrument that is easily broken. Before you buy a level, test it on a level surface to make sure the vials are accurate (opposite page).
Most levels contain one or more bubble gauges – sealed vials with a single small air bubble suspended in fluid – that indicate the level’s orientation in space at any moment. As the level is tilted, the bubble shifts its position inside the vial to reflect the change. This type of level is sometimes referred to as a spirit level because of the use of alcohol inside the gauge. There are also several types of electronic levels that offer digital readouts instead of using a bubble gauge.
Most carpenter’s levels contain three gauges: one for checking level (horizontal orientation), one for plumb (vertical orientation), and one for 45 angles. Some levels include pairs of gauges with opposing curves to improve readability.
Laser levels project highly accurate beams of light around rooms or along walls. Many styles automatically establish their own level orientation.
Make sure your level is accurate. Hold one side of the level against a flat, even surface (top photo), mark the location, and read the bubble gauge carefully. Pivot the level 180 and read the gauge again. Next, flip the level over and read the gauge. The bubble should give the same reading each time. If not, adjust the mounting screws to calibrate the bubble, or buy a new level.