All About Metal Roofs: from Aluminum to Zinc
Updated: Dec 8, 2020
Metal roofs are an increasingly popular option for homeowners looking to cut down on maintenance costs and access environment-friendly roofing. Versatile and diverse, metal roofs include a full range of options, with different materials and structures, varied advantages, and different methods of installation. Read on to find out more about metal roofs and determine whether this option is right for your home.
History of Metal Roofs
Metal roofs have a long history—dating all the way back to ancient times. Copper roof shingles have been discovered from as far back as the 3rd century B.C., when they were used on Sri Lankan temples; the ancient Romans also used copper as a roof covering for the pantheon. Metal roofs were also common in European medieval architecture, including on cathedrals and castles (the Elsinore Castle in Denmark, a famed site of Shakespeare plays, was equipped with a copper-roofed tower).
In America, metal roofing became common beginning in the nineteenth century, though lead and copper were used even earlier to cover cracks in roofing surfaces. The process of galvanizing base metal with zinc—to protect from rust—was developed by the 1850s, making metal roofs popular for homes as well as buildings like post offices and factories. Stamped sheet metal roof tiles became common in the early 1900s, often used to simulate clay material.
Types of Metal Roofs
Metal is a highly malleable material; it can be shaped to imitate other roofing materials, such as asphalt, slate, and tile.
R-panel metal roofs feature long, flat shafts; they’re low-maintenance, easy to install, and highly cost-effective. R-panel roofs are available in a range of colors and are a popular choice for both residential and commercial buildings.
Corrugated metal roofs are a classic option, often galvanized to prevent rust. The corrugated pattern of metal roofing tiles evokes a traditional look, making it a popular option with restaurants and shops as well as farmhouses. They’re often equipped with skylight panels and are available in a variety of patterns and designs.
Architectural metal roofs employ a system of interlocking panels to achieve highly weather-resistant roofs. The architectural design helps roofs hold up against both water and wind, making it an excellent option for homeowners in areas that face extreme weather.
Copper: Copper is the oldest and most commonly used material for metal roofs. The advantages of copper roofs include a rustproof material that resists scratches and wear. In fact, wear from longtime use makes copper roofs look better rather than worse: the “verdigris patina” that develops on rust roofs over time is considered a desirable aesthetic.
Aluminum: Lightweight and cost-effective, aluminum resists rust and is a popular choice for metal roofing materials. Homeowners often opt to paint or coat over bare aluminum for a more customized look.
Steel: Steel is a dent-proof, durable, and sturdy choice for a metal roof. To protect from rust, roofers typically coat aluminum materials with zinc. It’s a popular choice among business owners and homeowners alike, and is usually equipped with a paint finish for aesthetic purposes.
Stainless Steel: Stainless-steel roofs are a long-lasting option that don’t show signs of wear, rust, or corrosion. They’re often coated with additional materials for a matte-gray color that looks natural and appealing.
Alloy: Metal roofs can be constructed with a mix of different metal materials, combining the advantages of strength and durability with weathering and aesthetics. Zinc, copper, and steel alloys are the types most commonly used.
One reason why metal roofs are so versatile is that many different types of coating can be used to change their appearance and materials. Coating materials such as ceramic and epoxy are commonly used on metal panels; they help waterproof the roof, prevent rust, and reflect heat.
Copper roofs are amenable to a wide range of coatings, from clear coatings that preserve its warm, natural color to metallic coatings that help achieve a matte look. Copper roofs can even be coated with oil—including lemongrass, castor, and linseed—to exclude moisture, thereby enhancing a luster and depth in the roof’s color.
Opaque and lead-coated copper coatings are also sometimes used. Zinc-tin coatings can be used to approximate a desired look of exposed lead.
Advantages of Metal Roofs
Metal roofs are highly advantageous to a homeowner for a range of reasons, including exceptional durability and cost-effectiveness.
Durability: Metal roofs have a longer performance expectation that most other types of roofs. With a typical service lifespan of fifty years—or longer—metal roofs are an incredibly durable option.
Versatility: Because there is such a wide range of materials, coating, and structural styles for metal roofs, these roofs are incredibly versatile. They can be designed to match the existing aesthetic of a home or a neighborhood, and can be made to imitate traditional roofing styles for a cost-effective option that looks just as appealing. CertainTeed Matterhorn metal, for example, pairs a natural and authentic appearance with the stellar durability of metal roofing.
Easy Maintenance: Metal roofs are exceptionally easy to maintain. They’re light-weight and have strong structural integrity, so they’re resistant to extreme weather and daily wear alike. Homeowners with metal roofs will enjoy cutting down on the costs and time of maintaining their roofs.
Energy Efficiency: Metal roofs help cut down on homeowners’ energy costs by keeping the home cooler than most traditional roofing materials. They reflect solar energy rather than absorbing it, helping to keep homes cool.
Homeowners who live in hotter regions can enjoy not only the cool atmosphere in their home, but also the reduced cost of air-conditioning and other energy-consuming cooling systems. Metal roofs can also qualify for a federal energy-efficient tax credit, helping homeowners save.
One Indiana homeowner conducted his own study of the energy savings he made after having a metal roof for six months. The homeowner reported that his electric bills were the lowest he’d ever had, that his total energy savings topped $300 within sixth months, and that his energy consumption decreased around 28%.
These advantages make metal roofing more and more popular among homeowners. In fact, residential metal roofing is one of the fastest-growing sectors of the home improvement industry; it has more than quadrupled its market share over the past decade.
An Environment-Friendly Option
Metal roofs are considered the most environmentally-friendly and sustainable roofs on the market today.
Unlike many other roofing materials, metal roofs are 100% recyclable. They’re made with a minimum of 25% recycled material, according to the Metal Roofing Alliance, and the percentage often exceeds 25% depending on the specific type of metal used.
Existing homeowners should know that metal roofs can be installed over an existing roof, including over asphalt shingles. This not only cuts down on installation cost, it also eliminates the negative environmental effects that stem from disposing of roofing materials.
Metal roofing is also lightweight, cutting down on the environmental effects of the production process. A typical metal roof weighs half as much as the same amount of asphalt, so newly constructed homes can be designed with a more lightweight, environmentally friendly structure. Metal roofs consume less crude oil than asphalt during the production process. Because they have such a long lifespan, they are a more climate-conscious option that will produce less waste over time. Solar panels are also easy to install on metal roofs because of their durability, helping homeowners to reduce their carbon footprint.