Open Truss Roof Structure

Components of roof truss.

Open truss roof structure.

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. A roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof. Rafters have a tendency to flatten under gravity thrusting outwards on the walls.

In essence a roof built on trusses is much more structurally sound. The benefit of a truss over older structural designs like coupled rafters is that it provides longitudinal support. Roof framing has undergone a quiet revolution over the past half century. 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.

Trusses are gradually replacing the conventional rafters to the point that nowadays more than 80 percent of new residential construction uses trusses to support the roof. The buckling resistance is obtained from bs en 1993 1 1 2 by applying a reduction to the resistance of the cross section. A roof truss is supported by the exterior walls and span the width of the building.