Welded Purlin Shed Roof

Lay the first purlin at the ridge of the roof down to the chalk line beginning at either corner.

Welded purlin shed roof.

Purlins are usually connected to the main portal frame with cleats. 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. So when we orient the purlin horizontally we make the wall much stronger inside outside. In cold rolled steel sheds the cleats are bolted to the frame with purlins bolted to the cleats.

The purlin and the sheeting are weaker inside outside than they are up and down in this configuration. The cleats and purlins holes or punching are generally done to the aisc standardised structural connections with most fabricators manufacturers working within the standards. With the purlins welded to the face of the pipe the strength of the purlin duplicates the strength provided by the metal sheeting. This design is a lot stronger and more robust way of making a steel shed.

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. If your puttin up steel buildings its likely your charging by the square foot don t grind nothing use 1 8 5p or 5p setting depends on your travel speed i run hot and fast to get it done.