Levels can be used to measure, draw perfectly vertical lines and assure accurate cuts. Basic levels are available in variations that commonly include the spirit or bubble level, along with more advanced levels that include laser beams to light the way.
The spirit level is the most common type of level. Also known as a bubble level or carpenter's level -- shorter versions are called torpedo levels -- it works by centering a small bubble inside a tube of colored liquid. Spirit levels are used to establish vertical -- typically referred to as plumb -- or horizontal lines in relation to the floor or ground.
Horizontal Spirit Leveling
Step 1 Establish the Horizon
Place the level horizontally, parallel across an object or plane that you wish to level. This procedure is also referred to as "finding the horizon." This can come in handy when leveling a line for the installation of wainscoting or for leveling the horizontal members of a fence.
Step 2 Find the Lines
Hold the level as still as possible, and wait for the bubble to stop moving. Note the location of the bubble in relation to two lines or circles on each side of the water-filled tube. If the bubble is centered between the two lines, the level is perfectly horizontal, and no leveling is necessary. If the bubble is not centered, proceed to the next step.
Step 3 Level It
Tip the ends of the level up or down to center the bubble between the two lines to establish the true horizontal plane of the object.
Vertical Spirit Leveling
Step 1 Establish Vertical
Place the level vertically against an object or plane that you wish to find the true vertical, or plumb line. This procedure comes in handy when installing vertical moldings, or paneling. It's also vital for fence posts.
Step 2 Find the Lines
Center your gaze at eye level with the bubble tube at the top of the level. The tubes for vertical leveling are perpendicular to the length of the level; there's one located at each end. Allow the bubble to stop moving. Check the orientation of the bubble between the lines. If it's centered, the object or plane is perfectly vertical.
Step 3 Establish Plumb
Tip the bottom of the level to the left or right as needed to center the bubble between the lines to find the true vertical or plumb line of the object.
Optional 45-Degree Bubble
Torpedo levels often have a bubble tube slanted at a 45-degree angle. The procedure for establishing a perfect 45-degree line is exactly the same, except the level will be positioned at 45 degrees, instead of horizontally or vertically. The 45-degree bubble comes in handy when cutting braces or joists.
The laser level is the most advanced and one of the most accurate types of levels for sighting a level line across longer distances, to measure height, or establish plumb lines.
Step 1 Orient the Level
Place the level on a flat surface or object and turn it on. Or optionally hold it in your hand at a prescribed measurement on the wall. The laser beam will indicate a straight line.
Step 2 Center the Bubble
Check the orientation of a bubble inside a tube centered on top of the level. Tip the level up or down as needed to center the bubble between the lines.
Step 3 Level and Mark
When the bubble is centered between two lines, the projected beam is perfectly horizontal. Measure and mark the line on the wall as needed to present a perfectly level line between the laser level and the object or along the wall. Use it to install wainscoting, chair rail or picture rail trim, floor tiles or anywhere needed as a reference line.
Laser Level Options
Other versions of laser levels project lines vertically and horizontally at the same time. Use them for perfectly square corners, when trim runs vertically, or to install tiles or flooring perfectly straight across a floor.
Tripod-Mounted Laser Levels
Bigger, more powerful laser levels stand on a tripod and can project a beam across the ground at a prescribed level for foundations or long, straight installations outdoors. This type of level can also measure elevation by establishing a given height at the tripod and then project the beam across a distance to indicate elevation or height on a distant object.
Old-School Line Level
Line levels work similarly to laser levels, but instead of a beam of light, they employ a simple piece of string, stretched tight between two stakes. The line level is a simple, short bubble level that attaches to the string. Level the bubble by moving the string up or down as needed on the stakes. It's perfect for the installation of foundations, fences and outdoor landscaping and building.
Levels do much more than leveling. Carpenters, woodworkers and builders use them as a straightedge when appropriate or to draw plans. Most levels include a tape measure along one side that allows you to create drawings, or measure for cuts. Heavy-duty levels can be used as a guide for sawing or cutting by sliding the tools along the arrow-straight body of the level for accurate cuts.