How Close Do You Install Perlins Under A Metal Roof

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

How close do you install perlins under a metal roof.

The topic we want to discuss today is the purlin installation. Tin roofing also known as metal roofing is considered more durable than composition or wood shingles. The purlins not only give you something other than the existing roof to accept the roof panel fasteners they also create an airspace between the roof panels and the existing roof. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top.

Installing wood stripping under a tin roof. On metal frame building and the like you will likely see structural metal roofing installed on purlins that is what those 1x4 are purlins and those metal roofing panels are rated for that type of installation. Purlins are 2 by 4 feet and are installed much like metal roofing. If you are placing metal panels over an existing roof you still use purlins.

There are two ways to do this put in firring nailing though nails are not used any more for this strips or purlins in steel frame construction on the roof to support it or place the metal roofing directly on a flat surface like foam insulation board or the roof sheathing with roof water barrier in the correct position in the layer. 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. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. The purlins support the panels.

Metal roof purlins are installed horizontally under metal roofs. When installing a metal roof you want to make sure you are starting square. Secure the screws but do not overtighten. 3 remove old roofing and repair any damage start from the top of the roof and remove the old shingles along with the flashing underlayment and vents.

Installing non structural metal roofing on purlins will allow the panels to flex bend crimp and otherwise become damaged in some.