Steel Roof Purlin Design

Purlins are installed horizontally under metal roofs.

Steel roof purlin design.

The topic we want to discuss today is the purlin installation. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. Only design of purlin is explained in this video in a very simple way. Contact flexospan for information on custom purlin and girt structural steel dimensions.

The type and spacing of purlins is a design consideration which depends upon the incident roof loads as well as the limiting lengths of sheeting to be used. In structural steel or aluminum construction p urlins usually w shapes or channels transfer roof loads to the major structural elements supporting the roof. Purlins are non pressure treated 1 x 4 x 12 lumber that is installed on to the roof in a specific layout pattern and screw pattern. Steel roof purlins and wall girts are produced and available in house.

Metal roof purlins are installed horizontally under metal roofs. Purlins are 2 by 4 feet and are installed much like metal roofing. To watch how to calculate the load on purlin then plss watch this video. Engineered purlin metal mart offers a complete line of engineered purlin material.

They give added support to the roof and also provide a nailing surface for the end panels and drip edge. Available in cee or zee shape red oxide primed or galvanized 16 14 or 12 gauge sizes from 4 up to 12 flange widths of 1 1 2 up to 4 cut to your specified lengths hole punching available load tables available for all material. All spans to have 1 row of bridging. Cpe 0 9 and cpi 0 2.

Safe roof purlins spans. In timber construction purlins are nailed to the rafter or supporting trusses while in steel roof construction they are welded or bolted to the rafters or trusses by the means of cleats. The shape of cee purlins does not allow end lapping they are butted together. Roof purlin are members used to directly support roof sheeting materials and could be made of timber or steel.

Cleated or bracketed fixing only no flange bolting. Max roof span allowed 12m. Steel z purlins and z girts are also available with other depths and flange widths. Purlins are 2 by 4 feet and are installed much like metal roofing.

Next and the last video of this series will be on. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. High pressure zones kl 1 5 and 2 0 included. The safe spans below are suitable for sheds and class 1 structures with the following assumptions.

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Cee purlins are secondary steel framing members most commonly used as roof purlins wall girts and header jamb and sill for windows and doors on metal buildings.