How Much Slope Does A Metal Roof Need

Minimum metal roof slope depends on the roof profile building design climate and site location.

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. Low slope metal roofs require less material which reduces the overall load on the building s structure. Standing seam metal roofs with mechanical lock systems to ward off leaks can be successfully and attractively installed on roofs with at least a slope of 1 in 12.

I ve built many of those patio covers over the years it rains a lot in oregon and they ve been fine. 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. Most metal roofs will have minimum pitches of three in twelve but this might sometimes go down depending on whether there are special installation procedures issued by the manufacturer regarding that particular roofing material. 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.

To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12. Since it s just over a deck if it had at least that much i probably wouldn t comment. 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.