Shed Roof Purlins

Once the zinc coating has broken down the steel will begin to rust.

Shed roof purlins.

If there are gutters installed on the eaves the eave flashing should be installed to overhang the lip of the gutter by about 1 2 inch. Metal roof purlins are installed horizontally under metal roofs. Place corner pieces where panels will meet bends at the edge of the roofing. Purlins and girts are used longitudinally to support the roof sheeting which they were originally designed for.

Building trusses on site is easily done for a shed. 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. Metal roofing panels rated for architectural use attached to purlins horizontal pieces of wood or metal fastened to roofing trusses are structurally sound when installed according to your roofing manufacturer s instructions and local building codes. For many applications a layer of plywood underneath your metal roofing is an unnecessary expense.

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. A typical coating thickness is 275 g m. We offer four structural systems. The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed.

Do all roofing projects require purlins. A simple gable shed roof is often built using 2 4 or 2 6 lumber for the rafters and 2 4 for the collar ties. 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. Roof zed purlin systems allow for a flexible efficient range of solutions to roofing supports for a wide variety of cladding types.

Use 1 1 4 inch nails to cover the outline of the roof with strips of metal eave flashing also called edging. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. The rafters are angle cut at the ridge end and notched with a birdsmouth where it meets the top plate of the supporting wall. Purlins are 2 by 4 feet and are installed much like metal roofing.

Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. This design is a lot stronger and more robust way of making a steel shed. In structural steel or aluminum construction purlins usually w shapes or channels transfer roof loads to the major structural elements supporting the roof.