dwang

A dwang is a short horizontal timber or steel member installed between vertical studs or joists to brace them and prevent racking, the tendency of a frame to distort into a parallelogram under lateral stress. In timber-framed buildings, dwangs are typically 50 × 50 mm softwood or steel flats, cut to length and fixed between studs at intervals, usually one or more per panel, depending on stud spacing and height. The dwang resists shear forces from wind or earthquake loading that would otherwise cause the frame to shift out of square.

Dwangs are most common in light timber frame construction in regions where building codes require them, particularly in areas prone to seismic activity or high wind. In Australia and New Zealand, dwanging is standard practice in residential timber framing. The horizontal member works in combination with diagonal bracing or shear plywood panels, though dwangs alone provide some lateral stiffness when nailed or bolted securely at both ends. They are typically positioned so that fasteners can be driven through studs into the dwang ends, creating a rigid connection.

Installation and positioning

The spacing and placement of dwangs is determined by the span between supports, the stud size, and local building codes. In a 2.4 m high timber wall with 90 × 45 mm studs, dwangs might be installed at mid-height or quartered. They must be cut square to length and fitted snugly between studs to prevent the frame from rocking. Poor fitting or missing dwangs in multi-storey buildings can allow excessive deflection and cracking in wall linings.

The term is used primarily in Australasian carpentry; equivalent members in North American timber framing are called blocking, backing, or cross-bracing, depending on their function. The word dwang likely derives from regional dialect, and appears to have no direct etymological connection to other trades. In steel frame construction, dwangs are less common because the frame's inherent rigidity and bolted connections resist racking more effectively than timber does, though horizontal tie plates and column bracing serve similar stabilizing roles.