kingposts

A king post is a vertical structural member used in timber framing, particularly in roof structures. It extends from the apex of a roof down to the tie beam, which is the horizontal beam at the base of the roof structure that resists the outward thrust of the rafters. The king post's primary function is to support the tie beam and prevent it from sagging under the weight of the roof and snow load.

King posts are typically employed in roof trusses, which are triangular frameworks designed to span a space and support a roof. In a simple king post truss, the rafters rest on the tie beam, and the king post is suspended from the apex of the rafters, where they meet. The king post is often made of wood, but metal versions can also be used. Its size and shape depend on the span of the roof and the loads it is expected to bear.

The use of king posts allows for wider spans without the need for internal supports, making them an efficient and historically significant element in building construction. They are commonly found in older structures like barns, churches, and industrial buildings, though modern construction may utilize engineered trusses that achieve similar structural goals. The king post's presence is a key characteristic of certain traditional roof truss designs.