Framing

Also called: frame construction, frame and panel

Framing is the work of building a skeleton of jointed timber members: the frame that surrounds and holds a panel in a door or piece of cabinet work, or the structural skeleton of a whole timber-framed building. The term covers both a small-scale joinery technique and a way of building entire structures, and the two share a good deal of vocabulary and method.

Setting out and cutting a frame

In hand-worked framing, cutting the mortises (slots) and tenons (the tongues that fit them) comes before any grooving, rebating, or shaping cuts are made. The heavy framing chisel, also called a mortise chisel, is built to take hard strain and suited to the deep cuts framing demands; it can double as a deck chisel in shipbuilding, a piece of cross-trade tool use. Layout tools differ by tradition: a framing square, a large right-angled measuring tool, has its longer, wider arm called the body, while Japanese joiners plan the cut-outs for frame members using detailed sectional drawings and rulers instead. In the best-quality framed work, decorative moulds are set in place while the frame is being put together, rather than added afterwards.

Panels within a frame

Panels set into a frame are named for the direction of their grain: 'laying' when it runs horizontal, 'upright' when it runs vertical. One finishing style, called square-and-flat, leaves the door framing square-edged with plain panels about a third of the frame's thickness. A door counts as 'solid-moulded' when its moulding is worked directly into the framing timber rather than applied on top of it afterwards. Framing that encloses a triangular space, such as the space under a flight of stairs, cuts the heads of its panels to match the slope of the raking top rail, the sloped top rail that closes off the triangle. Solid-wood frame-and-panel construction of this kind still appears in fine reproduction furniture and small custom cabinet shops today, and sound oak panelwork framing depends chiefly on paying proper attention to the joints.

Joints that hold a frame together

A tenon that is oversized, fitted into a mortise that is overlong to match, leaves room for shrinkage to make the joint loose over time, and an overly long mortise weakens the frame member that contains it regardless. Some tenon variants address particular problems: an unequal shouldered tenon carries one shoulder set off-line from its partner shoulder, and a haunch, a short stub added at the top of a tenon, stops light from showing through the joint where a shrinking mortised member meets the member crossing it. For elaborate framing, draw-bore pins and oak dowels may be needed when the frame is finally glued up. Not every frame joint needs full strength: lap joints, where one member is notched to overlap another, suit frame assembly when only moderate joint strength is required, and work equally well in picture and mirror frames as in structural assemblies. Butt joints, where two square-cut ends simply meet, commonly form face frames in cabinet making. A centre-hung frame section, joined to the framing on either side of it by rebated joints, can act as a door in its own right once assembled this way.

Timber framing in building construction

Timber framing, in the sense of a whole building's structural skeleton, calls for advanced joinery, complex geometric setting-out, and a sound grasp of the structural forces involved. It let early builders use less wood than later methods, though it demanded greater skill and inventiveness from them. Historically, light-frame buildings used one of two main methods: balloon framing, whose wall studs run the full height of a two-storey building, or platform framing, built storey by storey instead. Some wall assemblies use timber stud framing, ready-made proprietary systems, or light blockwork rather than solid timber. A foundation can be capped and a timber frame's base formed using either heavy timbers or standard stick-framing lumber, and where a foundation wall must be permanent, careful choices of preservative-treated plywood, framing, and connecting fasteners all matter. In a stressed-skin panel, a plywood skin bonded to the framing adds strength and stiffness beyond what the framing alone provides. Japanese-style roof framing works on different structural principles again: its beams act as simple beams that must resist the bending caused by loads carried down through the end posts, which suits it to small buildings with short beam spacing, where its simple build is valued.