Shed Roof Purlins

Building trusses on site is easily done for a shed.

Shed roof purlins.

We offer four structural systems. Purlins and girts are used longitudinally to support the roof sheeting which they were originally designed for. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. In structural steel or aluminum construction purlins usually w shapes or channels transfer roof loads to the major structural elements supporting the roof.

Four structural systems are available all of which allow for a flexible and efficient range of solutions to roofing supports for a wide variety of cladding types. 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. 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. Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load.

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. For many applications a layer of plywood underneath your metal roofing is an unnecessary expense. 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. The corrosion protection system influences the life of a shed roof the base of the system is zinc coating called galvanising.

This design is a lot stronger and more robust way of making a steel shed. The rafters are angle cut at the ridge end and notched with a birdsmouth where it meets the top plate of the supporting wall. 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. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.

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. Use 1 1 4 inch nails to cover the outline of the roof with strips of metal eave flashing also called edging. A typical coating thickness is 275 g m. Place corner pieces where panels will meet bends at the edge of the roofing.

Do all roofing projects require purlins. Once the zinc coating has broken down the steel will begin to rust. Roof zed purlin systems allow for a flexible efficient range of solutions to roofing supports for a wide variety of cladding types. The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed.