Weight. Compared to the weight of tiles metal roofing is very lightweight. Sheet-metal roofing is lightweight, fire-resistant, quick to install, and great at shedding water. Because of the material’s light weight, you can save on engineering and building the supporting structure. In fact, if you’re building a house or an addition, you can often downsize or reduce the number of roof trusses. Metal reflects radiant heat from the sun, minimizing midday heat gain. This means you save energy needed for air conditioning during the day. Though the material itself is low in insulation R-value, metal roofing can be applied over insulation materials that has very high R-values. In addition, many systems utilize a dead-air space between the metal and roof deck to increase energy efficiency. Various profiles exist that are manufactured for specific slopes.