SteelMaster Metal Roofing Systems, Carports and Pavilions

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Galvalume™ Plus Coating

Do you need another reason to choose SteelMaster®? Well how about the best Warranty in the business. Our competitors say they stand by their buildings, but only SteelMaster offers a 30-year Warranty. SteelMaster can offer an unrivaled warranty because the buildings are made with superior quality steel. Download Galvalume Plus PDF. Galvalume™ offers these advantages over galvanized: • At least twice the corrosion resistance of traditional galvanized coatings of similar thickness under the same exposure conditions • Excellent protection at cut edges • Exceptional heat reflectivity resulting in lower energy load on buildings and improved interior comfort • A distinctive appearance, with a smooth, fine spangle and silvery metallic finish • High temperature resistance Galvalume™ coating is an alloy composed of 55% aluminum and 45% zinc by weight. The coating is metallurgically bonded to both sides of Dofasco’s high quality cold rolled steel sheet using a precise continuous hot-dip coating process. The result is a highly corrosion resistant coated steel that combines the barrier protection and extended durability of aluminum with the galvanic protection of zinc.

Galvalume™ superior corrosion resistance has been proven by actual exposure tests and confirmed through extensive field evaluations of real buildings. Atmospheric tests using flat coupon samples were conducted over 36 years in the USA and 17 years in Canada. The tests covered a variety of environments ranging from rural to severe marine.

An inspection of 25+ year old Galvalume™ roofs confirmed that they are still in excellent condition and are projected to last to 30 or more years before requiring major maintenance.

A Guide To Coating Thickness
Galvalume™ AZM180 coating will provide at least twice the corrosion protection of galvanized steel coated with Z275 (G90) zinc coating. The following chart shows the calculated coating thickness , based on the nominal weight per unit area and density. It is not a measured value, nor does it imply any type of specified limit.

Standard Coating Weights
AZM150 150 g/m2 minimum triple spot
AZM165 165 g/m2 minimum triple spot
AZM180 180 g/m2 minimum triple spot
CSP Coating: AZ210 210 g/m2 minimum triple spot

Size Availability
.30mm (.012") to 2.03mm (.080") thickness
1257mm (49.5") maximum width

The Advantages of Galvalume™ Coating
The coating makeup is a duplex microstructure that results from the aluminum-rich phase solidifying first, as the coating cools, forming a network of dendrites. Interdendritic spaces are-filled by the zinc-rich phase. The intermetallic layer is an Al-Fe-Zn-Si alloy that metallurgically bonds the coating to the steel substrate and further aids in corrosion resistance.

Cut Edge Protection
The aluminum-zinc alloy coating provides exceptional cut edge corrosion protection of the steel substrate by providing a long tem barrier against corrosive elements. This advantage over galvanized has been well documented from inspections of roof applications on buildings up to 25 years old. The greater corrosion protection of Galvalume™ will provide longer service life, especially in the more corrosive acid rain and coastal regions of North America.

Heat Reflectivity and Solar Reflectance
Bare, unpainted Galvalume™ product has undergone extensive testing to determine its solar reflective performance. Test results qualified Galvalume™ coated steel as an approved roof product by ENERGY STAR Program, both for low-slope and high-slope applications. On newly-manufactured Galvalume™ Plus, heat reflectivity was also rated above the minimum EPA requirement of 0.65. For weathered roofs over three years of age, the solar reflectance also exceeded the minimum EPA requirement of 0.50 for maintenance.