Also sometimes known as a strong back, a strongback is a type of construction that helps to enhance the strength of some type of structure by adding a secondary support at a key point in the design. The idea is to provide additional support at points in which the failure of the main support network would lead to the collapse of the structure as a whole. This type of additional element in construction can be successfully utilized in commercial buildings, homes, and even in the construction of boats and ships.
As it relates to the construction of a commercial building, a strongback is often in the form of a girder or beam that helps to reinforce the overall structure. For example, an additional girder or set of girders may be placed in close proximity to a girder that is positioned to bear a great deal of weight in the overall structure. Doing so creates a situation in which any damage to that central girder does not immediately lead to the collapse of the weight normally carried by that support. Instead, the burden shifts to the two strongback girders and makes it possible for repairs to be made before permanent damage to the structure takes place.
In a home, a strongback is often a beam that is used to reinforce the efficiency of floor and ceilings joists within the construction. With this application, the strongback joist works in conjunction with the beam to help keep floors and ceilings level, even if the support or weight-bearing beam should begin to deteriorate over time. The same general concept may be used to reinforce staircases, by attaching the strongback bracing to the stringers on the staircase, making it possible for the structure to remain stable even when subjected to stress that would normally cause the stringers to fail.
The strongback is also often used in the construction of different types of boats and ships. As with the supporting beam or joist found in the home, the strongback in the ship design often helps to provide additional support to the skeleton or frame of the vessel by running along the length of the ship and bracing the frames that make up the overall body of the ship. This makes it more likely that the framing of the ship will remain intact even if there is some type of hull damage sustained in a storm or some type of boating accident.
A strongback should not be viewed as a replacement for the joists or beams that it augments. Instead, this type of construction should be seen as a backup or support to the main element in the overall design, something that enhances rather than replaces the function of the other design elements. When executed properly, a construction element of this type can help protect the integrity of buildings and other types of construction, improving the chances of being able to repair damage and continue to make use of the structure for many years to come.