November 19, 2020
Are Metal Roofs Noisy?
In part one of our series on metal panel roof pitch, we looked at the engineering and strength considerations that need to be taken into account when designing or specifying a building. In part two, we’ll review how to make the right metal panel selection for your building end-use by looking at the building type and roof pitch to find the optimal combination of form and function.
Types of roof panels:
Different types of metal roof panels are better suited for certain roof pitches and this mostly has to do with panel rib height and how they’re seamed together. For instance, the lower the pitch, the taller the rib of the roof panel needs to be in order to optimize water carrying capacity. Also, the lower the pitch, the slower water runs off the roof; combined with wind pressure, this can hold water at the eave. As an example:
Building Type and Use:
Whether residential, post-frame or commercial, structures follow general design criteria regarding metal roof slope, based on to the building type and use. For instance:
Gabled v. Hipped: gabled roofs provide more interior headroom while with hipped roofs, endwall sheet height can be reduced, making for easier ordering and installation as you don’t have to cut/miter the sheets.
Solar Panels and Roof Pitch:
The geographic location of a structure will determine the angle at which the solar panels should be installed. Generally. the closer to the equator you get, the lower the slope the solar panels can tolerate as roofs closer to the equator have more consistent exposure to sunlight as compared to those farther away. If you plan to add solar panels to your metal roof, be sure to check the Solar Reflective Index (SRI) values and minimum slopes set by the ASTM and local governing codes. These standards will advise adequate slope based on your location as well as help control things such as heat island effects, etc. For more information on solar reflectance and how it is affected by the color of your metal roof panels, see our blog post on cool metal roofs.
Roof slope is a factor that affects many decisions when it comes to any metal building roofing project regardless of the building’s end use. When embarking on any metal roofing project, be sure that the panels you’ve selected meet local building codes and are produced by a quality manufacturer with knowledge and experience designing for different applications to ensure you get exactly what you’re looking for. For more information on metal panel selection for your building end-use and to learn more about recommendations on roof slope for different building types, contact your local ABC representative today.