What Is A Camber In Construction?

The architecture and construction industries have their own language and vocabulary. Some of the terms and devices used are founded in the craft of building and engineering. The use of arches and beams as decorative elements and structural devices includes the term "camber." Once you know what "camber" means, you will notice its use in furniture design, pottery design, road construction and building construction.

To camber means to slightly curve or bend. The word camber is typically used in describing a type of arch, truss or beam. In construction, there are many different types of arches and beams. What distinguishes a camber is its slight curve upward. Cambers are used in windows, doorways and interior structural devices such as trusses and arches. The term camber dates from the early 1600s and is French and Latin in origin.

A camber adds extra structural support to a wide span or space. Camber is used in long spans with the purpose of counteracting deflection due to load. Camber is used in bridge construction as well as buildings, churches and decks because calculations can be made to offset particularly heavy loads of weight, thereby dictating the actual upward curve or camber to be used.

Stone, wood and steel can be cambered, or arched. Sometimes timber has a natural camber, but a slight camber can also be added in milling wood. Cambering in milled beams happens between a 3500-degree radius and zero. Stone is usually placed piece by piece into a camber, with the upward most point of the camber referred to as the keystone. A cambered steel beam or arch is machined per required tolerances.

Cambering a steel beam involves elongating one side of the beam more than the other. It is referred to as deviating from the straightness of the edge. ASTM International, originally called The American Society for Testing and Materials, has standards that define the maximum allowable tolerance for the deviation required in cambering. Tolerance is stated as inches allowable per feet.

A positive camber arches upward. This is what is typically desired in construction. A negative camber sags. This can indicate a problem–wear and tear, deterioration or deliberate destructive manipulation–to a structure. Sagging is sometimes referred to as negative camber.