Tag Archives: galvanized metal roof

Commitment to Quality Residential Roofing: Why It Matters

The Metal Roofing Alliance and our members talk a great deal about quality.  In fact, it’s so important to us that “Investment Grade Roofing” is part of our logo.   Contractors may wonder why it matters so much – isn’t one metal roof just as good as any other?  The answer is NO in capital letters!

Veterans of the industry know that the metal roofing products on the market can vary greatly in quality and  value.  We’ve all seen sub-par products, such as those intended for agricultural applications, improperly installed in a residential neighborhood.  

As a condition of joining the MRA, all of our member manufacturers agree to adhere to strict industry codes regarding the quality of the products sold into the residential market.   

The Importance of Coatings

The type of coating applied to the sheet steel is a key factor in choosing the right product for residential use.  Two types of metallic coatings are used in metal roofing to prevent rust — zinc (galvanized) or zinc plus aluminum (galvalume).  These coatings provide a sacrificial barrier against the elements which prevents the iron from rusting.  Because it sacrifices itself to form zinc oxide or aluminum oxide, the thicker this layer, the more protection against red rust there will be. There are differing amounts of metallic coating used on sheet steel depending upon its final product application.

The numbers G-40; G-60; and G-90 refer to the ounces of zinc per 100 square feet of sheet steel coated. (top and bottom) So G-90 will have 90 ounces of Zinc- 45 ounces on each side per 100 square feet of roofing sheet steel.

For galvanized products, the MRA recommends a minimum of G-90 be used. For galvalume product used in residential application, the MRA recommends a minimum metallic coating of AZ-50.  This is in accordance with the Guidelines for Residential Metal Roofing published by the Metal Construction Association.  

However, if you want to be sure that you’re purchasing quality metal roofing for use on homes, the easiest thing you can do is to ask whether the manufacturer is an MRA member.  If the answer is yes, you’ll know that the product you’ll install is rated for residential applications.  A strong MRA member manufacturer can be your best friend in this business, providing training, specs for fasteners, underlayments, and ongoing support.

To learn more, visit our website: www.MetalRoofing.com

Galvanized Metal Roofs – Why Use G90 or Higher for Residential Roofing?

Galvanized panels are a very popular substrate for metal roofing.  Manufacturers often use terms such as G60 or G90 to describe their products.  What’s the difference? And which should contractors use in various applications?

Galvanized Defined

Galvanization is the process of applying a protective zinc coating to steel or iron, to prevent rusting.  After roofing panels are galvanized, they can be painted or granular-coated.  The grades of galvanized products correspond directly to anticipated field longevity. With galvanized substrates, the more zinc the better. These “G” numbers indicate how many ounces of zinc are applied to each 100 sq. feet of paneling. G60 has 60 ounces, G90 has 90 ounces and therefore provides better corrosion resistance. These numbers are directly related to increased longevity and long-term aesthetics for the roof.

Specifications Defined

The Metal Construction Association has developed a Guide Specification for Residential Metal Roofing that clearly defines which galvanized products should be used on homes. All MRA members must agree to adhere to or exceed the MCA’s Guide Specification for Residential Metal Roofing before they are permitted to join the association.  This same rule applies for both manufacturers and contractors.  For galvanized steel used in residential applications, the MRA recommends a minimum metallic coating of G-90. So, if you’re not sure of the coating of the panels you are installing on homes, it’s in your best interest to find out.  Again, the higher the number, the better protection from rust.

Metal Roof

Why It Matters

“Members of the metal roofing industry are constantly fighting the outdated ‘rusty barn roof’ image, and the Metal Roofing Alliance has made great progress in educating consumers about today’s beautiful, long-lasting metal roofing options.  Every bad roof installation is a step in the wrong direction,” says MRA’s Executive Director Bill Hippard.

Metal Roofs on Homes should not rust

In a competitive environment, it may be tempting to choose a lower quality (and therefore lower cost) steel panel when installing a new metal roof.  However, for roofers who are looking to build a business and remain in this growing residential market segment, that choice offers short term gain in exchange for long-term pain.  Whenever a lower-quality metal roof is installed, it’s almost certainly doomed for failure, resulting in customer complaints and a damaged reputation for all metal roofs.

Former customers are an excellent referral source, and a happy homeowner will recommend your business to their friends and neighbors.  The opposite is also true – install an inferior product, and you will hear about it as well as those same friends, neighbors and perhaps even the local licensing authorities.

For a list of MRA member manufacturers and the Investment Grade Roofing products they offer for residential installation, please visit our website.