Open Truss Roof Structure

A roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof.

Open truss roof structure.

A timber roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof trusses usually occur at regular intervals linked by longitudinal timbers such as purlins the space between each truss is known as a bay. Rafters have a tendency to flatten under gravity thrusting outwards on the walls. In most truss members only flexural buckling of the compressed members in the plane of the truss structure and out of the plane of the truss structure need be evaluated. A roof truss is a structural unit designed to frame a roof and to support the roof material interior ceiling insulation and forces caused by snow rain and wind.

The benefit of a truss over older structural designs like coupled rafters is that it provides longitudinal support. The buckling resistance is obtained from bs en 1993 1 1 2 by applying a reduction to the resistance of the cross section. Because of the stability of this shape and the methods of analysis used to calculate the forces within it a truss composed entirely of triangles is known as a simple truss. A roof truss is supported by the exterior walls and span the width of the building.

The simplest form of a truss is one single triangle. This type of truss is seen in a framed roof consisting of rafters and a ceiling joist and in other mechanical structures such as bicycles and aircraft. Roof framing has undergone a quiet revolution over the past half century.