New Construction Metal Roof Installed Over Purlins

For the convenience of your customers we provide installation guides and metal roofing installation how to videos to support their building projects.

New construction metal roof installed over purlins.

A standard retrofit sub framing system will not allow a positive attachment to the existing roof purlins. Measuring the outer perimeter existing profile of the roof panel skylight locations and modularity with the new metal roof rib spacing and identifying. 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. Our metal roof and wall panels qualify for underwriters laboratories ul class a fire rating ul 90 wind uplift rating and class 4 ul impact resistance hail rating.

Purlins are 2 by 4 feet and are installed much like metal roofing. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. The spacing of your purlins depends on the expected snow and wind load.

They re also simple to install. The actual installation of metal roofs on 1x or 2x purlins has been done for decades on ag and wood framed commerical buildings. The topic we want to discuss today is the purlin installation. Use 1 1 4 inch nails to cover the outline of the roof with strips of metal eave flashing also called edging.

Installing a metal roof is a complicated process with many details. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. Its use on residential projects is far less common but has been done a lot especially in rural areas. Place corner pieces where panels will meet bends at the edge of the roofing.