Installing A Metal Roof Over Purlins

You need to check the installation instructions from the manufacturer depending on whether the purlins firring strips are 1x or 2x material and how wide thickness metal gage of roofing steel or aluminum type of seams design wind and snow loading whether designed to be walked on or not etc i have seen it vary from as little as 4 inches clear gap between firring strips on lightweight aluminum to as much as 4 feet on very heavy gage steel standing seam roofing commonly around 1 2.

Installing a metal roof over purlins.

Snap a chalk line horizontally across the roof two feet down from the top. As long as the plywood under the shingle roof is in good condition this way can provide many benefits. Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails. 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.

It should overlap the edge of the gutter if you have them. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. The topic we want to discuss today is the purlin installation. The edging or eave flashing consists of metal strips that are used to cover the perimeter of the roof.

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. When using plywood nail it directly to the purlins and screw the metal roofing panels through the plywood into the purlins as instructed by the manufacturer. This method is used for trusses designed to be closer together from 2 on center up to a maximum of 5 on center. Set the second.

How to install metal roof purlins step 1. In this installation the vapor barrier is installed on the side of the insulation nearest the interior of the building. Run a tape measure from end to end along the rafters of the roof to determine how many purlins will be needed. Lay the first purlin at the ridge of.

Use your 1 1 4 in 3 2 cm nails to secure the flashing to the subroof. This is by far the most common way to install a metal roof.