Welded Purlin Shed Roof

In a structural steel shed the main portal frames and roof rafters are made from strong steel sections which are welded together and later bolted together.

Welded purlin shed roof.

With the purlins welded to the face of the pipe the strength of the purlin duplicates the strength provided by the metal sheeting. Lay the first purlin at the ridge of the roof down to the chalk line beginning at either corner. The purlin and the sheeting are weaker inside outside than they are up and down in this configuration. Fasten the purlin with 16d common nails into each vertical rafter.

Snap a chalk line horizontally across the roof two feet down from the top. Purlins and girts are used longitudinally to support the roof sheeting which they were originally designed for. This design is a lot stronger and more robust way of making a steel shed. In cold rolled steel sheds the cleats are bolted to the frame with purlins bolted to the cleats.

Bycajun welderdate05 03 2009 02 10 i welded my purlins 4 16ga and i used sa 200 6011 1 8 second gear 40 45 and it worked well. The cleats and purlins holes or punching are generally done to the aisc standardised structural connections with most fabricators manufacturers working within the standards. So when we orient the purlin horizontally we make the wall much stronger inside outside.