The surface temperature of a metal roof can be very high in hot climates, but not as high as shingles. While unpainted metal can reach 145 degrees in summer, black asphalt shingles can reach 168 degrees. Metal roofs coated with heat-reflective paint can feel up to 42% colder than unpainted metal roofs. No, metal roofs are no hotter than dark tile roofs made of asphalt or other standard materials, such as slate, for example.
Although it may seem counterintuitive, metal roofs work well in hot climates. In fact, they keep the house much colder than asphalt shingles, which could reduce maximum cooling demand by 10 to 15%. Metal reflects sunlight and keeps you cooler inside, while asphalt shingles, especially black ones, absorb heat from the sun, making the house much warmer. New, white or light-colored metal roofs with proper ventilation are better than old metal roofs, and special sealants can further cool the material.
In the United States, when working as a roofer, mainly with asphalt, one of the most common questions homeowners asked was: which is better? The answer depends on your priorities. Asphalt shingles are undoubtedly affordable and easy to install. Metal roofs are more expensive and require specialized knowledge for installation. Asphalt shingles have come a long way in terms of appearance and can be manufactured to look like wooden slats, shingles, and even slate roofs.
The constant thermal cycle wears out asphalt shingles and reduces their useful life. Because asphalt is absorbent, water can enter, freeze and dry, causing its structure to break. In addition, they are designed and installed with fixing clips or slotted screw holes that allow the thermal movement of metal with changes in temperature without breaking over time, according to the president of Classic Metal Roofing Systems, Todd E. This means that, in any climate, metal roofs have an average lifespan of 50 to 70 years, compared to 20 to 25 years for asphalt shingles.
In the case of asphalt shingles, most of the maintenance consists of penetrating the roof, where adhesives, metal gaskets and sealants are used. These sealants deteriorate over time and must therefore be replaced. And rubber pipe boots (the joint plugs for plumbing pipes that run through the ceiling) are also prone to breakage and need to be repaired or replaced. While asphalt shingles can withstand fire, metal roofs offer the best strength.
And while it's commonly believed that hail can easily dent a metal roof, that's a myth. Metal roofs are more efficient at handling the common impacts of hail than asphalt shingles. Metal roofs often are, especially if they're made of aluminum, which has a high scrap value. However, the process of separating and recycling asphalt shingles is much more expensive and is not yet common practice.
Unfortunately, 11 million tons of asphalt shingles reach landfills every year. Unlike asphalt shingles, metal roofs are usually made of some recycled material. The coating underneath the asphalt shingles consistently followed the surface temperature, dropping to 15 degrees below the outside temperature. However, the temperature in the airspace below the metal roof never fell below outside temperatures.
Therefore, while the surface temperatures of both metal and shingles were maintained side by side, the airspace below the metal roof was up to 20 degrees warmer than the airspace below the asphalt shingles. One of the reasons why many homeowners don't take advantage of the energy savings and durability of metal roofs is largely due to the cost of installation. Lower cooling costs are just one of the benefits of choosing to invest in a quality metal roof over shingles and other old materials. In addition, according to the EPA, the summer savings of a metal roof considered a cold roof are so significant in some regions that annual energy expenditure will continue to be lower overall with a metal roof, even if a little more heating is required.
One reason why so few American homes use metal roofs is because their initial cost is typically two to three times that of asphalt shingles. However, metal roofs are likely to compensate for their high price over time, especially in certain climates or in places where electricity is expensive. The Department of Energy asked the Oak Ridge National Laboratory to conduct a study on “The trade-off between solar reflectance and ventilation above metal roofing coating in residential and commercial buildings”. If your metal roof is located directly above an uncontrolled temperature room such as an attic insulation and ventilation will be a very important step in ensuring that heat doesn't build up in an enclosed space.
Metal roofs survive the elements well and remain intact when faced with strong winds hail and lightning; they are more likely to withstand extreme conditions such as hurricanes. Metal roofs are a more difficult material to install correctly leading to a higher price because they help better insulate and regulate temperature inside your home your HVAC doesn't need to invest as much energy in heating and cooling. A metal roof made of copper or steel will survive well for example but an aluminum one will eventually melt Metal roofs offer amazing energy savings largely due to their type of material but also because of their variety of finishes Asphalt shingles perform best in temperate climates while metal roofs can perform well in extreme hot or cold wet or dry conditions but cost more up front.
