It is important to note structural metal panel roof systems can be used for steep slope roof assemblies too.
Low slope metal roof details.
Low slope metal roofs require less material which reduces the overall load on the building s structure.
Another approach is to build a cupola or ventilated doghouse in the middle of the low slope roof an approach championed by joe lstiburek.
But the taller profiles like standing seam and pbr shown below can be installed on roofs with as low as 1 4 or 1 2 in 12 pitch.
Not only can low slope metal roofing contribute to the bottom line it can also contribute to leed credits which are awarded to buildings that use high recycled content and other green construction materials.
Generic valley treatment details for metal panel roofs for low slope with and without substrates are included in the mbma metal roofing systems design manual chapter 12 metal roof details.
If the upper edge of a low slope shed roof intersects a vertical wall the most logical approach in my opinion is to detail the roof as an unvented roof.
By low slope roofing we mean any roof that is pitched at less than 4 inches of rise in 12 inches of run or 4 12 pitch.
The panels have been designed for application over a wide variety of substrates on roof slopes as low as 1 2 12 pitch.
Structural metal panel roof systems can be used for low slope roofs because of their hydrostatic or water barrier characteristics.
Low slope metal roofs have simple geometries and are easier and less expensive to install that medium to steep slope roofs.
The most critical application points on low slope roof systems are at flashings penetrations and accessories.
Available in 12 16 and 18 widths tite loc and tite loc plus panels can be produced in 22 and 24 gauge steel or 032 and 040 aluminum.
Roof penetrations should be kept to a minimum and should be located within the flat of the panel where possible as opposed to near seams.
There is only one category of metal roof systems used in low slope applications structural metal panel.
Because of the shallow height of the undulating ridges of the 5v and corrugated profiles and the use of exposed metal fasteners to screw the metal to the roof deck they are limited to a slope that will shed rain quickly.
That includes soldered metal roofing or synthetic membranes.
Regular asphalt shingles and standard skylights will work at pitches of 4 12 or greater but at lower pitches you have to use different materials.
Problems at these points typically arise from improper application methods and the use of inappropriate or incompatible materials.
Minimum metal roof slope depends on the roof profile building design climate and site location.
