Roof Purlin Design Example

A common arrangement is a rafter and purlin system which combines purlins and rafters.

Roof purlin design example.

Design guide for cold formed steel purlin roof framing systems. Design of roof purlins. Roof purlin design roof purlin design. The designis based on the maximum yeild strength mn fysx as stated in the aisc manual 13th ed.

Roof purlin are members used to directly support roof sheeting materials and could be made of timber or steel. C purlin cee or c purlins are shaped like a squared off letter c. Z purlin the zee or z purlin is shaped like a letter z. They are often used for structural support in walls and as floor joists in addition to roofs.

Its shape allows the purlin to overlap with others at the joints. First the development of forces requiring anchorage in purlin roof systems is discussed. Forces in roof systems as presented in chapter 5 of the new aisi. This spreadsheet is to be used to check the adequacy of roof purlins for a specified combination of loads.

The roof support system is a ridgepole and either rafters which run perpendicular from the top of the walls to the ridge or purlins which run parallel to the ridge. In traditional timber truss construction purlins rest on the principal rafters of the truss. Design of purlin solved problem by prof l agarwal. For example a roof purlin with no transversal element other than sheathing between the extremities on the compressed flange will have an unsupported length equal to its overall length.

The four steps in the general methodology of the component stiffness method are presented.