A bubble level is a hand tool used in construction to determine whether a surface is level, plumb, or properly aligned.

A bubble level, also known as a spirit level, is a measuring tool used to check the levelness or vertical alignment of surfaces and structures. It consists of a sealed vial partially filled with liquid and an air bubble that moves to indicate alignment relative to gravity.

In construction, bubble levels are used for tasks such as framing, setting doors and windows, installing cabinets, and aligning structural and finish elements. Most bubble levels include multiple vials for checking horizontal (level), vertical (plumb), and sometimes angled positions. They are available in various lengths to suit different applications.

Accuracy depends on proper calibration and correct use. While digital and laser levels are common on larger projects, bubble levels remain a reliable, low-tech tool for quick checks and detailed work. Proper handling and storage help maintain accuracy over time.

Despite modern digital tools, bubble levels have been used in construction for centuries—and the basic design hasn’t changed much since the 17th century.

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