Search results
Results from the WOW.Com Content Network
A birds-mouth joint in a rafter, set upon a double top plate. Shown are the two cuts of the joint: the seat cut and the heel cut. In light frame construction, a birdsmouth joint or bird's beak cut is a woodworking joint that is generally used to connect a roof rafter to the top plate of a supporting wall. [1]
Compass rafter: A rafter curved or bowed on the top (the top surface of a rafter is called its "back") or both the top and bottom surfaces. Curb rafter: The upper rafters in a curb (kerb, gambrel, Mansard roof) roof. Hip rafter (angle rafter): The rafter in the corners of a hip roof. The foot of a hip rafter lands on a dragon beam.
If built using dimensioned timber, each rafter is usually jointed into the previous one. More commonly, these roofs are constructed with roundwood poles where each rafter is laid upon the previous one. In both of these approaches, the roof is assembled by installing a temporary central support that holds the first rafter at the correct height.
Pairs of opposing rafters were thus initially tied together by a horizontal tie beam, to form coupled rafters. But such roofs were structurally weak, and lacking any longitudinal support, they were prone to racking, a collapse resulting from horizontal movement. Timber roof trusses were a later, medieval development. [2] A roof truss is cross ...
Its archetypal form, sometimes incorporating or implying the projection of rafters or trusses over the exterior of supporting walls, is the underside of eaves (to connect a supporting wall to projecting edge(s) of the roof). The vertical band at the edge of the roof is called a fascia. A soffit of an arch is frequently called an intrados.
The top ends of the rafters often meet at a ridge beam, but may butt directly to another rafter to form a pair of rafters called a couple. Depending on the roof covering material, either horizontal laths , battens , or purlins are fixed to the rafters; or boards, plywood , or oriented strand board form the roof deck (also called the sheeting or ...
A view of a roof using common purlin framing. The purlins are marked in red. This view is from the inside of the building, below the roof. The rafters are the beams of wood angled upward from the ground. They meet at the top of the gable at a ridge beam, which has extra bracing to attach it to the rafters.
Catenary: An arched roof in the form of a catenary curve. Arched roof, bow roof, [11] Gothic, Gothic arch, and ship's bottom roof. Historically also called a compass roof. [12] [13] Circular Bell roof (bell-shaped, ogee, Philibert de l'Orme roof): A bell-shaped roof. Compare with bell-cast eaves. Domed; Onion dome or rather an imperial roof ...