Minimum Roof Pitch For Standing Seam

Roof pitch multiplier table.

Minimum roof pitch for standing seam.

Run in degrees and as percentage the minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. Lapped nonsoldered seam metal roofs with applied lap sealant must have a minimum roof slope of 1 2 12. Standing seam roof systems must have a minimum roof slope of 1 4 12. We recommend 5 degrees however due to site conditions and execution.

Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12. Standing seam manufactures allow applications of metal coverings on slopes of 12 or even more. Depending on the roof profile there are minimum roof slope requirements for each panel which need to be considered. Speaking about standing seam metal roof slope it is a general and a self evident knowledge that the steeper it is the faster it is for snow rain or drain to come down the roof.

A 3 degree roof pitch means just over 50mm in every metre so over 3 metres you only have 150mm to play with. The minimum slope for standing seam of roof systems shall be one quarter unit vertical in 12 units horizontal 2 percent slope. Minimum metal roof slope depends on the roof profile building design climate and site location. The minimum pitch for roll roofing is 2 12 or 2 inches rise to 12 inches run.

In country with heavy snow and tough winter days the metal roof minimum slope is recommended to be 1 12. The minimum pitch for a standing seam metal roof is 1 4 or 3 inches rise to 12 inches run. Modified bitumen roofing requires a minimum roof pitch of 1 4 12 or greater. Degrees to pitch rise in run table.

You can often see such examples of use over metal decks. For a 1 12 pitch roof the only metal product i recommend is a mechanically seamed standing seam. There are some opinions that standing seam metal roof minimum slope is 12 but it increases the possibility of leaking on the few first days of snow arrival. Sig zinc and copper recommend that the minimum pitch for a standing seam zinc roof is five degrees with an absolute minimum of 3 degrees.

Typically large footprint single story warehouses and pre engineered metal buildings will utilize low slope metal roof systems. For this sort of system the panels are secured to the roof using hidden clips and then a seaming machine is used to crimp the seams closed so they will be water tight.