How Close Do You Install Perlins Under A Metal Roof

Purlins are 2 by 4 feet and are installed much like metal roofing.

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. Tin roofing also known as metal roofing is considered more durable than composition or wood shingles. Installing wood stripping under a tin roof. 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.

They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. 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. Secure the screws but do not overtighten. They give added support to the roof and also provide a nailing surface for the end panels and drip edge.

The roofing is manufactured in panels that. The washer under the screw head should seal to the surface of the. When installing a metal roof you want to make sure you are starting square. If you choose to omit the plywood from a residential construction install a vapor barrier between the purlins and the metal roof or plan to spray closed cell foam insulation between the rafters to eliminate the temperature differential between the air in the building and the metal.

The purlins support the panels. 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. 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. The topic we want to discuss today is the purlin installation.

If you are placing metal panels over an existing roof you still use purlins.