Metal Roof Installed Over Purlins

They give added support to the roof and also provide a nailing surface for the end panels and drip edge.

Metal roof installed over purlins.

The second way to install a metal roof over a shingle roof is with the use of purlins or battens. If there are gutters installed on the eaves the eave flashing should be installed to overhang the lip of the gutter by about 1 2 inch. 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 are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top.

We do recommend it however. 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. 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. The topic we want to discuss today is the purlin installation.

Place corner pieces where panels will meet bends at the edge of the roofing. Although you can install corrugated metal roofing over shingles for the best foundation it is recommended that all the old roofing be removed. This is by far the most common way to install a metal roof. Do all roofing projects require purlins.

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Work at a comfortable steady pace trying not to rip up or carry off too much old roofing at once. Purlins are 2 by 4 feet and are installed much like metal roofing. As long as the plywood under the shingle roof is in good condition this way can provide many benefits.

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.