|
Steel is commonly recognized as a strong material. When unprotected and exposed to the weather, however, steel oxidizes rapidly and red rust forms. If the steel is left unprotected, it will probably rust through it in a matter of just a few years.
In order to make steel last longer, it is first protected by a coating of zinc or a mixture of zinc and aluminum. The two coatings commonly used are galvanized and galvalume®. Galvanized is 100% zinc, while galvalume® is 30% zinc and 70% aluminum.
Panels on Morton buildings are sometimes coated with galvanized and sometimes with galvalume®, depending mostly on panel placement and us.
The common coatings for galvanized are G90, which is 9/10 of an ounce of zinc per square foot; Morton uses G90. Many others use a G60 galvanize coating, which is 6/10 of an ounce of zinc per square foot.
When galvalume® is used on Morton buildings, we specify AZ55, which is a minimum coating of 55 hundredths of an ounce per square foot; many others use an AZ coating, which is 5/10 of an ounce of zinc per square foot. Once again, we use the top-of-the-line coating, whether our steel is protected by galvanized or galvalume®.
|