Search results
Results from the WOW.Com Content Network
A lookout, [1] lookout rafter or roof outlooker [2] is a wooden joist that extends in cantilever out from the exterior wall (or wall plate) of a building, supporting the roof sheathing and providing a nailing surface for the fascia boards. When not exposed it serves to fasten the finish materials of the eaves.
Monitor roof: A roof with a monitor; 'a raised structure running part or all of the way along the ridge of a double-pitched roof, with its own roof running parallel with the main roof.' Butterfly roof (V-roof, [8] London roof [9]): A V-shaped roof resembling an open book. A kink separates the roof into two parts running towards each other at an ...
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.
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.
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 ...
Historically, roof pitch was designated in two other ways: A ratio of the ridge height to the width of the building (span) [6] and as a ratio of the rafter length to the width of the building. [7] Commonly used roof pitches were given names such as: Greek: the ridge height is 1 ⁄ 9 to 1 ⁄ 7 the span (an angle of 12.5° to 16°);
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 hammer-beam is a form of timber roof truss, allowing a hammerbeam roof to span greater than the length of any individual piece of timber.In place of a normal tie beam spanning the entire width of the roof, short beams – the hammer beams – are supported by curved braces from the wall, and hammer posts or arch-braces are built on top to support the rafters and typically a collar beam.