Add the metal panels.
Installing metal roof with purlins.
Always begin working at the point with the longest peak to eave distance.
Run a tape measure from end to end along the rafters of the roof to determine how many purlins will be needed.
Snap a chalk line horizontally across the roof two feet down from the top.
Set the second.
The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed.
Purlins are dimensional lumber that are fastened to the top chord of trusses connecting them together for bracing purposes.
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.
This is by far the most common way to install a metal 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.
The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.
You also need to add.
Installation of pole barn purlins.
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.
Spacing is typically 24 on center in low snow loads and is reduced based upon truss span and snow load.
Do all roofing projects require purlins.
As long as the plywood under the shingle roof is in good condition this way can provide many benefits.
During the roof installation or re roofing process after the roof sheets are prepared it is time to support their framework by installing purlins.
Take care the first piece is aligned precisely perpendicular square to the edge.
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.
Lay the first purlin at the ridge of.
Most metal shingles will be attached to the roof using metal shingle.