How Much Slope Does A Metal Roof Need

3 12 1 2 12 and 1 4 12.

How much slope does a metal roof need.

I e 4 inches of rise per 12 inches one foot of run. The most common slopes are. If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12. Minimum slope for metal roof realistically any more than 1 4 per foot would okay at all but the most windy times.

To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. Metal roof slope is expressed by a ratio indicating the roof pitch which notes the vertical rise of the roof in inches for every 12 inches the roof runs horizontally in other words dividing the vertical rise and its horizontal span. Metal should never be set up on a completely flat roof since they were not designed to handle pooling water which will lead to premature rusting and deterioration. Typically large footprint single story warehouses and pre engineered metal buildings will utilize low slope metal roof systems.

Minimum metal roof slope depends on the roof profile building design climate and site location. I ve built many of those patio covers over the years it rains a lot in oregon and they ve been fine. Since it s just over a deck if it had at least that much i probably wouldn t comment. Low slope metal roofs require less material which reduces the overall load on the building s structure.