What is timber frame construction?
Timber frame homes are known for their beautiful structural wooden beams visible throughout the interior. An ancient construction technique used across the world, timber framing was originally brought to North America by European settlers and remained common until the early 19th century. Advances in technology, such as large powered circular saws, enabled mills to churn out large quantities of smaller dimensional lumber, which was easier to transport. These small framing members made it possible to build a “stick-frame” home with just a small crew–a technique that is relatively unchanged to this day.
While timber frame construction is still in use, it has evolved from the purely structural purpose that it once served. In today’s homes, timber frame construction is also used to showcase the aesthetics of the wood since it remains exposed towards the home’s interior.
Many different tree species are used for a timber frame, including Douglas fir, Sitka spruce, Eastern white pine, red cedar, oak and Interior Alaska white spruce. The trees are handcrafted or milled into large beams. In the United States, there are a number of suppliers who cut custom beams according to a computer-aided design plan sent to them by a builder.
At the building site, the beams are assembled into a structural frame that is fastened together with a combination of carefully fitted interlocking wood joints and wooden pegs and splines. A traditional timber frame structure does not use metal connectors of any kind, and each frame is a completely unique combination of joinery types. For instance, some substructures are built like wooden furniture, where the connecting beams use mortise and tenon joinery, a process through which two beams are cut so that one has a square or rectangle opening (the mortise) into which the other beam (the tenon) fits perfectly. Usually joints of this type are held together with exposed wedges or pegs and have the additional benefit of great strength. [A similar construction technique, post-and-beam, uses metal braces and bolts to connect beams.]
After the timber frame substructure is erected, it is enclosed, often using structurally insulated panels (SIPS), to complete the home’s envelope. Most timber frames homes have open interior designs to showcase their exposed architecture. Plus, interior walls are not needed for structural purposes.
Timber frame homes come in all sizes, from small cabins to expansive homes. While timber frame construction tends to cost more than traditional stick-frame construction, the extra planning, materials, and labor results in a truly unique and durable home. Today, timber frame construction fills both a practical and artistic role in creating a home that is both a shelter and a work of art.