Queenpost

Queenpost, also written queen-post and sometimes queenpost, is a type of timber roof truss used in traditional timber-framed buildings to span medium to long bays. It is defined by two upright posts that rise from the tie beam to support the roof structure, allowing a wider interior space than a simple king post truss.

Structure and function: A crown beam or upper chord runs between the tops of the two posts, and rafters run from the outer walls to this upper member, transferring roof loads to the posts. The posts are braced with diagonal members and struts to counteract thrust. The arrangement distributes weight to the walls and is efficient for longer spans with limited timber.

History and usage: Queen post trusses appear in medieval and early modern timber-framed buildings across Europe and in colonial North America. They were favored for their balance of rigidity, ease of construction, and economical timber use, enabling wider bays than earlier simple trusses while avoiding the complexity of a long king post system. Today they are preserved in historic restorations and appear in some new-builds that use traditional timber framing.

Variations and related terms: There are several regional variants of the queen post truss, including different bracing patterns and the use of a collar beam for added stability. It is related to other two-post roof trusses, such as the crown-post and king-post systems, and is often distinguished by having two vertical supports instead of a single king post.