Even after years of excellent growth, there is still a lot of room for metal roofing to expand. According to the National Roofing Contractors association’s most recent annual survey, in 2005 the overall share of metal roofing was 4 percent of low-slope new construction, while the share for new steep-slope installations was 28 percent. While metal can be found on virtually any roof, it still takes an investment not only to buy it, but to sell and install it as well.