What is a Cantilever Beam?

A cantilever beam is a beam that is only supported on one of its ends. The beam bears a specific weight on its open end as a result of the support on its enclosed end, in addition to its structural integrity. Cantilever construction is popular in many kinds of architectural design and in other kinds of engineering, where professionals use terms like end load, intermediate load, and end moment to identify how much a cantilever beam will hold. The term moment is related to torque and to a theoretical load on a beam.

In residential architecture, cantilever design is often used for creating balconies and other extensions above ground level. Famous architects like Frank Lloyd Wright were known to take advantage of cantilever beam construction to provide for parts of a building that protrude from a supported section. The use of cantilevered setups and similar cantilever engineering is also often seen in bridges and similar projects. Carpenters might think of cantilever design in terms of wooden beams, but in other kinds of projects a cantilever design is applied to a concrete slab or a metal girder.

A specific use of cantilever beam construction is often part of a temporary construction project. While a bridge or other project is in transition, cantilever design provides for structural integrity while only one side of a beam is supported. Later, that beam may be supported on both sides. Engineers can show diagrams of how cantilever design will help ensure stability mid-way through a building project as part of a safety study.

Architects and engineers also use cantilever beam structures for the overhangs that are often a part of various buildings. Airports, university campuses, office complexes, and other areas will often include exterior structures that use cantilever beam construction for different intentions in building design. These overhanging elements can provide shelter from the elements or a decorative aspect to a building. In some cases, an "open style" cantilever design fits into a modern or artistic design for a space, where planners have blended practicality with aesthetic appeal.

Those who are interested in observing how cantilever design is used in modern engineering can easily find many visible instances of this engineering method at work in their local communities. A detailed study of this kind of design can better prepare a student for entrance into an engineering or architectural program. It can also increase a student's understanding of how professionals implement this kind of design to both residential and commercial projects.