Metal roofing is generally made of steel, aluminum, or copper. Rolls of 24- or 26-gauge steel sheets are given a metallic coating to prevent rust, followed by a baked-on paint finish.. Aluminum sheets don’t require the metallic coating but do get painted. Copper, often called a natural metal product, is neither coated nor painted, because it weathers without corroding. It is sometimes used for special features, such as the roof of a prominent bay window. These rolls of Metal are then rolled to form onsite to create a standing seam roofing system this is a very strong and durable metal roofing solution.
Steel roofing products are coated with either zinc (galvanized) or a mixture of aluminum and zinc (galvalume or zincalume). Of the two, galvalume offers the longer service. The coatings are offered in several thicknesses—the thicker the coating the longer the service, and the higher the cost.
The Metal Roofing Association (MRA) recommends a galvanizing thickness level of at least G-90 for residential applications and an AZ-50 or AZ-55 designation for galvalume coatings
The primary benefit of metal roofing is durability. Manufacturers routinely offer 50-year warranties and even lifetime, non-prorated warranties.
Metal roofs are lightweight, sometimes allowing them to be installed directly over old roofs. And when metal roofing is painted with specially formulated “cool pigments”, solar energy is reflected and emitted (rather than radiated as heat into the attic).
Additionally, metal roofs are effective in preventing the spread of fire when hot embers fall on them (i.e., from brush and forest fires). In fact, some insurance companies will give you a discount if you have a metal roof. In addition, metal roofing is made with a large percentage of recycled metal—often 95 percent—and when its useful life is done, it can be recycled again. No worries about it filling up dwindling space in landfills.
The panels are structural grade steel, with a minimum tensile strength of 52 KSI min. They are rigid enough to tolerate reasonable loads, while allowing profile designs without the risks of cracking or significant elastic recovery.
Aluminum-Zinc Alloy Coating
Protection for the rigid steel material is achieved when the steel passes through a bath of molten aluminum-zinc alloy. This coating combines the protection and strength of both aluminum and zinc. A significant benefit of the zinc component is its ability to protect exposed areas such as cut edges, drilled holes and scratches. Developers of the aluminum-zinc alloy coated steel have captured exposure data indicating corrosion protection of the underlying steel for more than 50 years in most environments.
Acrylic Priming System
An acrylic coating is applied to both sides of the panel immediately after the application of the aluminum-zinc coatings. We developed this priming system in association with our steel suppliers to provide a uniform substrate that enhances the adhesion of subsequent coatings.
The basecoat is formed by applying a custom designed acrylic resin binder. This specially formulated paint coating is made in two colors that will blend with the various stone granule colors. The basecoat serves two functions:
metal roofing Metal Roofing triangle It serves as an adhesive that bonds the stone granules to the base steel.
metal roofing Metal Roofing triangle It protects the underlying material from water and UV light.
The basecoat’s adhesion process is found in its excellent ability to adhere to both the granules and the underlying acrylic priming system. We achieve optimum UV resistance with the use of a pure acrylic resin; the strongest polymer capable of being made into a water-based paint.
Ceramic Coated Stone Granules
A protective coating, as well as an attractive appearance is provided by stone granules. They further enhance the resistance to UV light while providing an array of colors. These ceramic coated granules are sized and applied in such a way to insure maximum coverage of the basecoat; therefore, allowing another layer of protection against water erosion.
An acrylic overglaze is applied as a final coating that gives the granules a semi-gloss appearance. This tough, thin, acrylic finish bonds to the granules and encapsulates them with a coating that enhances the panel’s resistance to physical damage.
Call TRS today for a metal roofing consultation.