Terms For Roof Truss Members

When a roof is to be provided for a building which does not have interior supports and the exterior walls are more than 12 m apart a roof truss will be a convenient arrangement to support the roof.

Terms for roof truss members.

A roof truss consists essentially of the following components. Bearing width the width dimension of the member providing support for the truss usually 3 or 5 bearing must occur at a truss joint location. The top members of a truss are known generically as the top chord bottom members as the bottom chord and the interior members as webs. Truss members form a series of equilateral triangles alternating up and down.

Roof cap the total roof assembly members located above the wall line such as beams trusses plates purlins decking bridging ceiling roofing etc. A percentage increase in the stress permitted in a member based on the duration of the load causing the stress acts on the member. Hangers connect carried trusses to the carrier or girder. 4x2 truss has its members have the nominal 2 face up for plate embedment the 4 2 truss is a nominal 4 deep rather than a nominal 2 deep.

Components of a steel roof truss. The following diagram shows the terms used for general roof truss members. 4 2 design is used for shallow floor trusses. The terms pitch and slope are simply two different ways of expressing the same measurement.

The following diagram shows the terms applying to gable end roofs. I upper chord members. There are two main types of timber roof trusses. Scupper an opening in a roof usually faced with metal flashing to drain water from the roof at a given point.

Truss members are made up of all equivalent equilateral triangles. The uppermost point of a truss. Saddle a covering on the ridge of the roof so that water will drain. A horizontal or inclined member that establishes the lower edge of a truss usually carrying combined tension and bending stresses.

The same roof has a 4 12 or 1 3 pitch. A metal plate connected wood truss is a roof or floor truss whose wood members are connected with metal connector plates. Cantilever that structural portion of a truss which extends beyond the support bearing the cantilever dimension is measured from the outside face of the support to the heel joint.