Steel Rafter And Purlin Roof Construction

The purpose of purlins.

Steel rafter and purlin roof construction.

In architecture or structural engineering or building a purlin or purline is a horizontal structural member in a roof. Rafters to support the metal strap along its whole. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. For many applications a layer of plywood underneath your metal roofing is an unnecessary expense.

Let s take a look at the most common types of metal roofs for houses. The typical spacing standards for residential and commercial buildings are about 1 to 2 foot. The rafter and wall plate. Building control guidance note purlin and rafter roofs timber sizes and construction details.

Purlins are installed horizontally under metal roofs. Also known as sheeting rails purlins create the roofing members of the secondary framing of a steel building. Boxspan roof frames and rafters are suitable for use with both steel and timber framed homes. Boxspan is extremely efficient in roof framing.

Long spans and light weight make architectural such as cathedral ceilings exposed trusses and roomy lofts more feasible than ever. 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. 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. The support system for the roof is comprised of ridgepole and rafters or purlins.

J l neal subject. Do all roofing projects require purlins. Purlins and girts are used longitudinally to support the roof sheeting which they were originally designed for. Purlins support the loads from the roof deck or sheathing and are supported by the principal rafters and or the building walls steel beams etc.

An affordable option and easier to lay than shingles tin is the most commonly used type of metal roofing. Roof frames rafters roof beams lintels. Whether you are looking to install a metal roof on a shed or a house it s important to know the difference in the various types of metal roofs available. These structural supports run perpendicular across the rafter beams.

We do recommend it however. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. This design is a lot stronger and more robust way of making a steel shed. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top.

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 heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet.