Installing Metal Roof With Purlins

Installation of pole barn purlins.

Installing metal roof with purlins.

Lay the first purlin at the ridge of. Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load. Most metal shingles will be attached to the roof using metal shingle. Work up from the initial row starting at the lower corner in a diagonal pattern staggering the shingles to prevent gaps.

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. Add the metal panels. The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed. Snap a chalk line horizontally across the roof two feet down from the top.

You also need to add. During the roof installation or re roofing process after the roof sheets are prepared it is time to support their framework by installing purlins. This is by far the most common way to install a metal roof. As long as the plywood under the shingle roof is in good condition this way can provide many benefits.

Do all roofing projects require purlins. The structure of purlin helps to shift some of the loads that put on the metal sheeting to the main building construction by ensuring that the whole things stay in their place and adding structural integrity. When installing a metal roof over an existing roof insulate the spaces between the wood strips with rigid insulation to prevent condensation before installing the roofing. Run a tape measure from end to end along the rafters of the roof to determine how many purlins will be needed.

Take your first sheet of metal and place it on the roof so that it overhangs the edge at least 3 4 in 1 9 cm. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Take care the first piece is aligned precisely perpendicular square to the edge. Set the second.

How to install metal roof purlins step 1. Always begin working at the point with the longest peak to eave distance.