Metal Roof Installed Over Purlins

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.

Metal roof installed over purlins.

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. Although you can install corrugated metal roofing over shingles for the best foundation it is recommended that all the old roofing be removed. As long as the plywood under the shingle roof is in good condition this way can provide many benefits. Place corner pieces where panels will meet bends at the edge of the roofing.

Use 1 1 4 inch nails to cover the outline of the roof with strips of metal eave flashing also called edging. The purlins are screwed or nailed down to the roof deck depending on how the metal roofing manufacture has testing for their roofing panels and then the metal is installed to the purlins. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top.

Metal roof purlins are installed horizontally under metal roofs. The topic we want to discuss today is the purlin installation. We do recommend it however. Work at a comfortable steady pace trying not to rip up or carry off too much old roofing at once.

This is by far the most common way to install a metal roof. Purlins are 2 by 4 feet and are installed much like metal roofing. Do all roofing projects require purlins. The spacing of your purlins depends on the expected snow and wind load.

3 install 1x4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1x4 purlins over the shingle roof.