For a home being built by Homestead Heat of Whatley, MA, the clients opted for an exposed timber beam in the center of the house. This beam carries the second floor and serves in place of a an engineered, laminated beam that would have been boxed in with trim boards. Instead we were able to use a locally sourced, locally sawn 8×12 Eastern White Pine timber. Instead of using one long timber, which would be impractical in terms of size and expense, I used a technique called “scarfing” to join two smaller pieces into one. There are a variety of scarf joints available to the timber framer, but the one I selected, referred to as “stop-splayed and tabled with undersquinted butts and wedges,” is particularly well-suited to resist twisting and bending. It is also very pleasing to look at and in this case the scarf has a very central visual position in the home.
Choosing a hybrid timber and stick-framed house, as opposed to a whole timber frame, is an affordable way for clients to get the beauty, craftsmanship, and visible strength of a timber frame in high visibility parts of the structure, while allowing for the efficiencies of a stud wall construction everywhere else.
(Click on any picture to enlarge it)
Here you see some of the markings used to guide cutting of the joints.
The two finished halves of the scarf joint.
The first wall of the house goes up. This energy-efficient home is being built with two 2×4 walls that will give 10″ thick walls filled with blown in cellulose. The incorporation of the timber framed elements with the outer walls and floor system was very straightforward.
An amazing tool, called a chain mortiser, allows for efficient cutting of mortises, which are the slots cut into timbers to receive “tenons” on the ends of other timbers. The mortise and tenon connection is the basic joint at the heart of timber framer structures and is also used in a variety of fine-woodworking applications.
Here you see one of four posts with its tenon on top. The tenon will plug into a corresponding mortise on the underside of the 8×12 beam. You also see one of the diagonal braces, also with tenons on both ends. All tenons are secured with 1″ diameter oak pegs.
The beams have now been sanded to remove any markings from the raising process and oiled. The white oak pegs and wedges take on a rich color when oiled and set off nicely from the pine. Joists to carry the second floor are attached with hangers to the center beam. All but a few inches of the beam will be visible once the ceiling is installed.