How Much Slope Does A Metal Roof Need

Typically large footprint single story warehouses and pre engineered metal buildings will utilize low slope metal roof systems.

How much slope does a metal roof need. 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. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. Since it s just over a deck if it had at least that much i probably wouldn t comment. 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.

Low slope metal roofs require less material which reduces the overall load on the building s structure. 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. 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.

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. Minimum slope for metal roof realistically any more than 1 4 per foot would okay at all but the most windy times. 3 12 1 2 12 and 1 4 12.