Modern Metal Roofing Materials
A growing trend in the home roofing industry these days is the metal roof. With qualities of light weight, durability and fire resistance, there are various metal roofing materials and systems to consider.
Types of Metal roofing Materials Used
The primary metals used to make metal roofing materials include aluminum, steel, stainless steel, copper, and zinc alloys. Each metal roofing material has unique properties that affect its appearance, durability and price.
Heavier and more durable than aluminum, steel is a popular choice for metal roofing. Coated with zinc and sealed to provide a finish that protects it against rust and corrosion, a modern steel roof, installed properly, can last fifty years or longer.
The coatings typically consist of a bottom coat of epoxy primer, which provides additional adhesion, and an acrylic top coating, which is baked on to add protection and color that will withstand harsh sunlight, rain, snow and ice.
Stainless steel is another popular, but more expensive, metal roofing material that is highly resistant to rust and corrosion. A Terne coating may also be used to give stainless steel roofing material a more natural, matte-gray finish.
Aluminum roofing materials are extremely lightweight, making them another choice for home roofing. While aluminum doesn’t rust, it does need to be painted or coated to provide a more attractive appearance. The coatings used on aluminum roofing are similar to those used on steel roofing materials.
Copper has been used as a roofing material for centuries and offers a rust-free surface that is naturally resistant to scratching or peeling and develops a natural patina with time that is quite attractive. However, copper is extremely expensive and thus, less commonly used as a home roofing material these days.
Metal roofing Finishes
As described above, metal roofing materials often have a factory-applied protective layer applied in order to provide superior protection from the elements and to give the materials a more attractive appearance. The type of coatings used varies by manufacturer, the metal used and the desired look to be achieved in the final product.
Metal roofing materials may also be left uncoated in some cases, giving it a naturally weathering appearance and is more commonly found in metal shingles or shingle panels made from aluminum, copper, zinc or stainless steel.
Galvanized steel can also be used in manufacturing metal shingles or shingle panels, with a factory-applied paint system used to bake on a protective coating using fluoropolymers, producing a metallic-coated carbon steel roofing material.
Other types of coatings used on metal shingles and shingle panels include epoxy and ceramic granules or crushed stone chips, used to achieve the appearance of stone and further protect the metal roofing material.
Types of Metal roofing
Structural and non-structural, or architectural metal roofing materials are the two basic types of metal roofing in use today for residential purposes. Structural metal roofing is attached directly to lathe boards or purlins and doesn’t require solid sheathing underneath; the roofing material adds rigidity and integrity to the structure of the roof, thus its name.
On the other hand, non-structural metal roofing does require a solid substrate underneath, in which case oriented strand board, a metal roof deck or plywood sheathing is used.
Metal roofing has evolved substantially with new technologies and systems being introduced over the last twenty years. Where corrugated metal roofing with its heavy and unsightly waving ridges, was once used for sheds, barns and commercial-type outbuildings, today’s metal roofing materials have improved greatly in terms of durability and appearance.
Two primary types of metal roofing systems are most commonly used today; standing seam roofing systems and metal roofing “shingles”. Within each of these two types, there are many variations and each manufacturer offers its own metal roofing systems.
Standing Seam Metal Roofing Systems
Standing seam metal roofing materials have been used on barns and industrial buildings for decades, but more recently, these systems have evolved and improved to become more attractive and popular for residential use.
Made using a roll-forming manufacturing process, standing seam roof panels have a seam at one end and a lock on the other end, so that they interlock with clips for easy installation and a clean, attractive look. Seams where the roof panels are joined will be turned up, making them higher than the roof’s drainage level, providing excellent water-tightness and snow shedding capabilities, which makes them most popular in mountainous locations.
A standing seam roof does require additional labor versus other types of roofing systems, since the panels must be custom cut to properly fit the dimensions of a home’s roof. But the distinctive look and excellent durability have made standing seam metal roofing systems increasingly popular.
Metal Shingle Roofing Materials
At the other end of the metal roofing materials spectrum are individual shingles made from metal, but designed to simulate the look of wood or asphalt shakes or clay, stone or slate roof tiles. In many cases the shakes or tiles are formed into multi-shingle panels for easier installation.
The advanced coating and painting processes used today enable a wide variety of colors, textures and styles to be achieved with metal roofing shingles. Metal shingles are available in steel, copper, zinc, aluminum and stainless steel materials.