Terms For Roof Truss Members

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.

Terms for roof truss members.

Truss members form a series of equilateral triangles alternating up and down. A roof truss consists essentially of the following components. A roof s slope is the number of inches it rises for every 12 inches of horizontal run a roof with a 4 in 12 slope rises 4 inches for every 12 inches of horizontal run. Hangers connect carried trusses to the carrier or girder.

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. Scupper an opening in a roof usually faced with metal flashing to drain water from the roof at a given point. The uppermost point of a truss. Saddle a covering on the ridge of the roof so that water will drain.

Closed in which the bottom chord is horizontal and at the foot of the truss and open in which the bottom chords are raised to provide more open space also known as raised bottom chord. A percentage increase in the stress permitted in a member based on the duration of the load causing the stress acts on the member. A metal plate connected wood truss is a roof or floor truss whose wood members are connected with metal connector plates. 4 2 design is used for shallow floor trusses.

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. 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. I upper chord members.

There are two main types of timber roof 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. Roof cap the total roof assembly members located above the wall line such as beams trusses plates purlins decking bridging ceiling roofing etc.

Truss members are made up of all equivalent equilateral triangles. 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. Components of a steel roof truss.