They would say use a low slope approximately 5 12 and keep the snow on.
Minimum pitch for metal roof snow slide off.
The minimum slope for lapped non soldered seam metal roofs without applied lap sealant shall be three units vertical in 12 units horizontal 25 percent slope.
Roof pitches of 3 12 4 12 5 12 or 6 12 work best for metal buildings in snow country.
Corrugated metal roofing has the same minimum pitch.
The pitch is measured in inches of vertical rise per foot of horizontal run and the 5v crimp profile shown above requires a minimum slope of three in twelve or 3 12 3 inches vertically per 12 inches horizontally.
So in general the shallower pitch can be more dangerous with bigger slides.
Begin by measuring 12 inches on your level and marking it with a pencil.
That means there is at least 3 of vertical rise to the roof slope for every 12 it goes back horizontally.
Standing seam metal roofs which allow snow to slide more easily might do.
You can safely measure the roof pitch from inside your attic with a level that is either 18 or 24 inches a tape measure and a pencil.
The minimum pitch for metal roof shingles and lapped non soldered panels is 3 12.
The recommended minimum roof pitch for shingles is 2 12 or simply two units of vertical rise to every twelve units of horizontal span.
However it is regrettable that many installers usually ignore this requirement due to the desire for a quick installation process.
Anything less than 1 12 pitch is a huge mistake in snow prone climates.
In an effort to solve the problems associated with moving snow and ice i have heeded the experience and resources of european construction industry and have implemented their ideas with great success.
Slopes greater than 6 12 will tend to shed snow regardless of the texture of the material on them so roof slopes should be configured to avoid shedding anywhere people might be walking or exiting.
Most residential metal roofs require at least a 3 12 roof pitch and have no maximum roof pitch.
That is a 14 degree angle.
Anything over a 6 12 pitch tends to make massive amounts of snow slide off the roof without warning.
The higher the roof pitch the more often the snow slides off.