One of the most striking elements of any timber frame structure is the truss. Designed to be aesthetically stunning and structurally sound, trusses provide beauty and great strength. In timber framing, we use many different types of trusses, with each serving their own specific purpose. Below, we've explained some of the most common truss types found in timber frame construction.
The king post is the most common type of truss you'll see in timber frame construction, and provides a solid foundation for any structure from bridges to houses. This truss is defined by a central “king post” that starts at the tie beam and may or may not extend slightly beyond the rafters. In many instances, a king post truss will include two struts at or just below the center of the post that join into the rafters to provide extra structural strength. However, a well-designed and built king post truss is also strong enough to stand without the struts.
The queen post is the next most common truss type found in a timber frame structure. Queen post trusses are designed to allow for longer central openings at the center of the truss, making them ideal for homes or commercial structures with planned attic space. This truss type is defined by the use of two central supporting posts, which may or may not have struts extending from the sides of each post to the rafters for extra strength and support.
Hammer beam trusses are as strong as they are beautiful and ornate. This truss type is primarily found in homes and pavilions with vast open ceilings, as the center area of a hammer beam truss is very large and open. For that same exact reason, many cathedrals make great use of hammer beam trusses in their construction.
The design of the hammer beam truss is slightly more complex than that of the king post or queen post truss. The simpler form of the hammer beam truss is characterized by a small post and collar tie at the top for stability, with two hammer posts and hammer beams on either side connecting to the collar tie for added strength. The hammer beams are further supported by braces that link into wall posts.
More ornate hammer beam trusses may feature extra complex elements such as curved ties or central ribs. When ribs are added, they add an extra dimension, more beauty, and greater stability.
The scissor truss looks basic and simple, but don't let that fool you! These strong, slightly complex trusses are designed primarily for buildings, and help support sloping roofs. Scissor trusses are found in all sorts of settings, but you see them a lot in pavilions because of their open nature. Scissor trusses are named as such because they are comprised of two top and bottom chords each that intersect en route to connecting to the rafters, therefore creating a “scissor” pattern.
“Jambe de Force” translates into English as “leg of strength”, which a jambe de force truss easily demonstrates. The jambe de force truss is used primarily in buildings as well, seen in many cabins, homes, and pavilions with vast open roofs. A jambe de force truss looks almost like a hammer beam truss, but more triangular. You'll find a collar tie and post at the top, which is buttressed by jambe de force braces and central beams that provide a great deal of strength and support.
ARE THERE OTHER TYPES OF TIMBER FRAME TRUSSES?
Yes! Covering these five most common types of trusses only scratches the surface of the truss types used in timber framing. The best way to learn about other timber frame trusses, and to discover which timber frame truss might be best for your project, is to connect with our knowledgeable timber framing pros. Give us a call at (931) 484-7059 or fill out our online contact form to schedule a chat or a meeting. We look forward to hearing from you!