The following notches represent some of the typical joinery in our timber frames. The use of traditional tools and methods allows us a flexibility and precision in joinery design and fit that other companies, relying more completely on modern machinery cannot match. Some of the notches offer striking exposed joinery, adding to the distinct and unique atmosphere of your home.
This joint is practically the definition of a timber frame. Most of the joints that go into a frame are variations of this joint. A mortise is the slot or cavity cut into the wood, while the tenon is the projection end of a timber that is inserted into the mortise.
Adding a shoulder to the mortise-and-tenon makes a considerable difference in strength. by having the lower surface of the beam project into the post, the full width of the beam supports the load rather than just the width of the tenon. This allows the joint to bear three to four times more weight than the simple mortise-and-tenon.
Scarf Joint, Scarfing
The early settlers were able to hew out timbers of practically any length from the enormous trees of their virgin forests. Today, such trees are raare and we must rely on scarfing to produce the longer timbers. Scarfing is that method of joining or splicing two timbers end to end.
This popular notch (from furniture making) is commonly used in true timber framing ot join smaller members such as joints and purlins. The wedging effect of the dovetail and the weight of the timber lock this joint into place.
This is the notch which is cut into the base of a rafter. Generally found attached a the post, the notch also helps to keep the rafter from spreading due to the outward forces fro the weight of the roof.
The knee brace is a small timber that is framed diagonally between a post and a beam, using a mortis-and-tenon joint. The rigidity of the frame is greatly dependent upon the effect of properly fitted knee braces.
Anchor-Beam Joint (Dutch Tenon)
The Pennsylvania Dutch used this variation of the shouldered mortise-and-tenon where exceptional pull-out stresses were encountered. The protruding tenon can be rounded or carved to create visual interest without affecting strength.
Embellishments are the fine finishing touches give to the timber frame. Planed and sanded timbers are carefully carved, chamfered or beaded with router and chisels. The result is a very attractive, rich and refined appearance.-
What is a Structural Panel? Why Do You Use Them?
SIP (structural insulated panel) is a general term used to describe a foam core panel that has interior and exterior cladding already applied. Typically they have a urethane (isocyanurate) core. The thickness of this core determines the R-value of the panel. R-26 to R-42 is the common range. Actual foam thickness is usually the same as standard lumber thickness (3.5", 5.5") in order to facilitate jamb installation to accept door and window units.
The most common exterior cladding on SIPs is oriented stand board (OSB). Siding and roofing can be applied on this skin after the panels have been installed. Inside finishes such as drywall or tongue and groove boards are applied on the interior skin by the panel manufacturer at their plant.
There are many advantages to using SIPs. They completely enclose the frame, providing protection from the elements within the insulation space, thermal bridging is totally eliminated. The permeability rating of the core eliminates the need for an independent layer of vapour barrier. The splining system between panels allows for the injection of expanding foam and the structure becomes virtually airtight. As we pre-cut panels at our shop, site disturbance is kept to a minimum. With the assistance of a crane, the timber frame is then quickly enclosed as the panels are hoisted directly from the shipping trucks and installed.
SIPs are nailed directly to the timber frame. If a future addition to the structure is planned, we will use screws to make later removal easier. As recommended by the panel manufacturer, we use ring shank hot dipped galvanized nails or ceramic coated screws.
Because 4'0" is the standard panel width, we try to incorporate into the frame design a 4'0" o.c. frequency for framing members (rafters or purlins) to eliminate waste. We ensure all panel seams occur on a timber, particularly on the roof. On walls, the panels create a shear wall when properly fastened and splined.
Bent Configurations and Options
A bent is the structural arrangement of timbers that make up one cross-sectional piece of the timber frame. A number of bent options are possible, each defining interior space differently while featuring attractive joinery variations. It is generally the bent that determines the shape of the house, fixing its height and width. The following bent designs represent jus a few of the many configurations available.
The configuration of the hammerbeam permits great expanses of space unobstructed by connecting timbers. the result is a truly beautiful timber frame.
This particular bent forms a gable roof and highlights a variation of the Dutch tenon. the length of the bent posts can be increased to form a story-and-a-half knee wall or two story house.
A modification in the roof design makes more usable space under the roof available.
Saltbox with Framed Overhang
This well known example of colonial architecture creates a very handsome and energy efficient timber frame home. The ling roof line protects against a cold northerly exposure, while generous amounts of glass collect a warm southerly sun. Several types of converging joints and elegant carved pendants form the overhang.