Metal Roofing Warranties:
What You Need to Know
While metal roofing is known for its strength, durability and lasting beauty, some metal roofing products do perform better than others. Contributing factors include quality of design, substrates, coatings and manufacturers' fabrication processes. Proper metal panel selection begins with the ultimate end-use for the panels. For example, residential and high profile projects often call for an entirely different level of panel quality than a shade and shelter application. The information below describes what characteristics and manufacturing processes to look for when selecting a metal panel.
Warranties are also a consideration when selecting a metal panel. Consumers often associate warranty with dependability and performance. This is not necessarily the case. Just because a warranty has an extended time frame (45 years or even a “lifetime”), it does not necessarily mean that the warranty is better or that the product offers better performance. We encourage you to fully read and understand your supplier’s warranties.
Let’s look at an example from the automotive industry…
According to JD Powers & Assoc. nameplate ranking, which car offers better dependability?
| Warranties vs. Vehicle Dependability |
THE KIA RIO |
 THE LEXUS SC430 |
 |
| Price | $11,110 | $65,355 | |
| Basic Warranty | 5 years 60,000 miles |
4 years 48,000 miles |
|
| Powertrain | 10 years 100,000 miles |
6 years 70,000 miles |
|
| Roadside Assistance | 5 years 60,000 miles |
4 years no mileage limit |
|
| As you can see in the table to the right, although the Kia offers warranty packages longer than the Lexus, it is ranked last in vehicle dependability. | |||
In the long run, the best way to avoid a painful relationship with a metal product is to invest in a high-performance component that appropriately fits your application. In other words, don't shop for a warranty - shop for a product from a manufacturer that has a stake in that product's success. At McElroy Metal, we engineer high-performance, application-specific metal components with warranties that fit the bill.
| How do I judge metal component performance? |
| By substrate: |
There are two types of substrates: Galvalume® and Galvanized. Performance testing shows Galvalume® is better - backed with a 25-year Steel Mill Warranty. Galvanized has no warranty. However, galvanized substrates are still popular and do offer good performance if the grade matches performance characteristics. Galvanized grades depend on the amount of Zinc in the alloy. The simple fact is that the more Zinc on the substrate the better the performance. For example, a G100 substrate has 66% more Zinc than a G60 substrate and will do a better job of resisting corrosion. McElroy Max-Rib provides a choice of panels with a menu of Galvalume® and Galvanized substrates and coatings to match your project. |
| By coatings: |
Looks for the Long Run: Three types of coatings are available - best, better and good. Kynar 500® (PVDF) is the "best" for long life, color retention and chalk resistance. Best for any project. Siliconized Polyester is the "better" coating and performs well in general use. Polyester is the "good" coating and performs well in shade and shelter or basic applications. |
| By manufacturing process: |
Thermoforming: McElroy warm-rolls all Max-Rib siliconized polyester panels. Thermo-Forming prevents tension-bend cracking, providing corrosion protection for increased longevity, visual appeal and value. |
| Know Your Warranty Terms |
Often warranties are designed to protect the manufacturer. In fact, warranties are written with acceptable levels of failure. When reviewing and comparing warranties, you should know the following terms. |
| Fade: |
 Fading occurs when the environment attacks the pigment portion of the paint system. When testing for fade, all chalk and other surface impurities are removed using cheese cloth and detergent prior to testing. The test is then conducted in the area that was cleaned, often resulting in a “claim denied”. Performance Fact: Kynar 500 coatings offer the best protection against fade. |
| Chalk: |
Chalking occurs when environmental conditions cause degradation of the resin. As the resin degrades, it takes on a whitish appearance called chalk. Again, levels of failure are built in to the warranty. Performance Fact: Kynar 500 coatings offer the best protection against chalk. |
| Film Integrity: |
Film integrity is the ability of the coating to stay adhered to the metal substrate. Film integrity has little to do with fade and chalk ratings. Therefore, a bright red wall/roof can be a muted pink (or even white) with the film still intact. Film integrity is being used in the metal panel industry to extend the length of warranties. Performance Fact: Kynar 500 coatings offer the best film integrity. |
| Substrate Warranty: |
Galvalume® carries a warranty from the steel mills. Galvanized does not. Galvalume® warranty protects against perforation (rust-through) of the substrate. Surface rust, as shown in the photo is not covered by the Galvalume® warranty. Performance Fact: Galvalume substrates or high zinc content (G100 or greater) galvanized substrates offer the best protection against corrosion. |
| Red Rust Warranty |
 Most "red rust warranties" protect against the accumulation of rust on the panel's flat areas - away from cut edges, where rust is most likely to occur. Performance Fact: Proper building design and installation practices will lessen the risk of edge rust. Click here to download our good design practices pdf on proper base designs. » |
