Roof Truss Stress Points

Battens purlins timber sections spanning trusses to support roof covering.

Roof truss stress points.

A roof truss consists essentially of the following components. Spanning from truss to truss which is meant to carry the load of the roofing material and to transfer it on the panel points is called a purlin. For bundles of trusses greater than 45 and up to 60 in length at least two lift points are required. When high winds hit.

1 to the curvature or may be solid timbers laid to the curved pattern with or without their top surfaces sawed to the curvature fig. The bending stresses about both. Hence the length of the purlin is equal to the width of the bay i e the spacing of the trusses. Apex peak the uppermost point of a truss.

A normal rainfall typically won t cause damage to your roof unless it has already been undermined by other weather. Roofs are designed to withstand weight and tension by dispersing it over trusses or rafters. Bowstring trusses are usually analysed for direct stress as though the top chord were in a straight line between panel points. Stress points can indicate signs of roof damage winds.

A percentage increase in the stress permitted in a member based on the duration of the load causing the stress acts on the member. Trusses that are banded together into a bundle are stiffer in comparison to a single truss but lifting a bundle of trusses by the peak can still cause undue stress and damage. Trusses that are banded together into a bundle are stiffer in comparison to a single truss but lifting a bundle of trusses by the peak can still cause undue stress and damage.