Commercial roofing is usually reserved for the covering of large facilities. The products consist primarily of flat roof or low slope roofing materials. They range from long structural metal panels that form as structural members of the building structure itself to the hot asphalt BUR (Built-Up Roof), flat roof systems and all the variations in between.
These types of facilities are vast and the expense of a steeper sloped truss roof is prohibitive. The engineering design for providing vast floor spaces is far more suited to flatter roof structures. Consider the size the roof would be if your favorite supermarket or mall was to utilize a similar designed roof as the one on your home. It would be massive to say the very least.
It is typical to see the same materials as are on your roof used on the decorative mansard awnings and dormers that define the building’s front facade. These provide the architectural design appeal for the building as opposed to revealing the plain appearance of the flat roofing material.