The truss system used in a timber frame home might be chosen to suit structural needs or aesthetic reasons. But what is a truss, you might ask? A truss is a timbered unit composed of a combination of vertical posts, girts, main rafters, struts, and knee braces fastened together to form a structural bridging system over an open space. These are then joined together by a peg to complete a finished section called a bent. Together, the truss and bent are used to support your home at the ends, center, or both when raised.
Styles of truss systems vary, and the one most suitable for your project will depend on the design of the timber frame home or timber frame building, the personal design aesthetic you want to achieve, load capacity, and the overall room layout. Whatever choice you make, you’ll know they’re doing their job to support the timber frame building.
A few popular types of timber frames trusses are king, queen, scissor, and hammer beam. Don’t be afraid to mix different timber frame trusses together to make a statement in your home that shows your personal style. Like mixing in a triangle, the simplest timber frame truss, with a hammer beam truss that is considered to be more dramatic for its large span. Before making a decision, explore the pros and cons for each timber frame truss and consult with a professional for their expert opinion.
King Post Truss: This is likely the most popular truss in the timber frame industry—largely due to its design—and also the most cost-effective. And from an engineering perspective, it has the greatest load-carrying capacity but still provides a cozy feeling.
Queen Post Truss: Very similar to king post trusses, but less popular due to the reactions of a heavier load. It looks like a rectangle within a triangle and does not put weight on the center of the main tie beam like a king post does. It also visually lowers the ceiling height, offering a more intimate feel for your space.
Braced Scissor Truss: When the bottom chords, or scissors, are half lapped properly at the center joint, this is a very strong truss. It is capable of sustaining heavy snow loads, making it ideal for steep pitches. These timber frame trusses are definitely for those looking for a unique look.
Tied Rod Scissor Truss: This truss may require walls around the perimeter and perhaps some additional lateral bracing. When it’s only point loaded, this truss performs well. It does not perform as well laterally due to the lack of braces. This style is often used in a nonstructural fashion.
Hammer Beam: The hammer beam truss can be used as a structural truss up to approximately 28 feet wide. That’s why it’s often used in large interior spaces and creates vaulted spaces. After that, when heavily loaded, it will want to spread. A great way to conquer this is to add a tie rod, which enables you to build a structural hammer beam truss up to 40 feet wide and greater.
After determining which timber frame trusses will work best in your custom home or great room, contact the experts at Mid-Atlantic Timberframes. We’ll guide you through determining your timber frame floor plans and how best to incorporate what timber frame trusses you need.