Timber Frame Joinery
What is timber framing?
Timber framing is a distinctive style of building construction in which heavy timbers frame the structure instead of more slender dimensional lumber (for example, 2 x 6-in.). Timber framing was a building practice used throughout the world until toughly 1900 when the demand for cheap, fast housing brought dimensional lumber to the construction forefront. In the 1970s, craftsman revived the timber framing tradition in the United States and have ushered the design style into the modern era.
One of the most defining elements of a timber frame is its unique joinery. Heavy timber is joined together via mortises and tenons, then secured with wooden pegs.
What are the differences among dimensionally built, log homes, post and beam, and timber framing?
Dimensionally built structures (sometimes called stick built) are framed with slender dimensional lumber—lumber in preset sizes that is readily available at lumberyards.
Log homes and structures are built of logs stacked horizontally, forming the walls.
In post and beam structures, upright posts support horizontal beams. These may be built of logs (round) or timber (milled to square). Post and beam structures are sometimes made of timber that is held together by metal brackets.
Timber framing is a specialized version of timber post and beam that is built like furniture, using wood joinery such as mortise and tenon, held in place with wooden pegs.
As designs become more intricate and code requirements more stringent, the distinction between some of these common terms becomes blurred. For example, timber frames may require engineered connectors in some joints. These connectors can be hidden inside the joint instead of attached to the timber surface, preserving the traditional timber frame appearance while making use of non-traditional technologies. Also, hybrid structures are prevalent, where timber framing and stick building are each used in the construction of different parts of a building.
What is joinery?
Joinery is what ties timbers together, in traditional timber framing. The ends of timbers are carved out so that they fit together like puzzle pieces. A hole about an inch in diameter is drilled right through the joint, and a wooden peg is pounded in to hold the joint together.
The universe of possible joints is quite large and complex. Common joints include mortise and tenon, dovetail, tying joint, scarf joint, and lap joint. There are many variations and combinations of these and other types of joinery.