Wider panels allow for greater spacing between rafters.
Spacing for purlins forfiber glass roof panels.
To install corrugated roofing start by cutting your panels to length with an angle grinder.
R panel install 11 21 11 metal roofing materials metal the r panel metal roofing panel is an industry leader purlins decks and fasteners must be designed to resist all loads imposed on the panel ng winds 2 1 3 4 5 install metal directly to wood frame use maximum 5 purlin spacing install metal not recommended for heated.
There is a chance of damaging roofing sheets if you are failed to do so.
An engineer will use a load chart in order to determine the spacing between metal purlins.
Without a set of blueprints with a pe s seal you have no option but to follow the inspectors gig.
However engineering determines the optimal spacing between the purlins.
While panels may not fail under heavy snow loads strain at fastening points can cause slight cracking.
To determine how far apart to set rafters measure the width of the metal panel and then the width of the first hill and valley of the panel.
A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel.
This will depend upon the type of panel that is used and the thickness of the steel.
Table is based on section properties or actual load tests available upon request.
These roofs are commonly problematic because the rib spacing is typically inconsistent thus not permitting a standard factory notched hugger sub purlin to be used.
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.
The wider the roofing panels the greater spacing distance you should put.
The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.
In heavy snow areas 500 series or greater panels are recommended and closer spacing of purlins should be considered.
Fyi we run purlins on 3 5 feet on center depending on size of purlin.
There are countless old corrugated roofs out there with 2 5 2 67 2 75 and 4 25 rib spacing as well as other ribbed type panels such as the 7 2 industrial rib roof panel.
The width of metal panels will determine the rafter spacing.
When looking at the ends of the rails the purlins shapes look like the letter c or the letter z the eave purlin marks the first purlin at the wall connection.
Beginning at the outside edge of your roof place each panel directly onto the purlins that are attached to the roof trusses.
Screw line spacing for metal roofing over metal purlins.
On a standard load most designs call for purlin placement at five foot intervals.
Next pre drill holes on the end and side ridges of the panels spacing the holes 6 to 8 inches apart.
