Are All Metal Roofs Created Equal? 8 Factors that Determine Quality
Something is weighing heavily on me these days. It’s the lack of education and depth of knowledge of many, if not most, roofing contractors. I had a contractor send me an email recently and, while I am paraphrasing a bit, here’s what he asked me:
“All of this talk you make about different types of metal roofs seems like hocus-pocus to me, Todd. I’m a contractor, and I know what a steel roof is. All metal roofs are really the same, aren’t they?”
Interesting comments from an industry professional, don’t you think?
Sadly, almost every day I hear from a frustrated homeowner someplace in North America because a contractor installed a metal roof on their home and, in one way or another, it’s not performing.
Here’s an example:
In mid-June, I had a homeowner text me whose house has huge flying gables and the contractor installed an R Panel roof on it with an enclosed gable channel that is trapping every bit of roof debris, ice, and snow – and overflowing with water that is getting into the home.
The fact is, there are many variants available today in metal roofing. And, while early on in our industry (say 30 – 50 years ago), new products were being developed which were better in terms of performance, the trend today is very much toward the development of cheaper products which can be woefully lacking in performance.
And, realistically, there may be justifiable applications for both high and low-quality products. What becomes a major problem, though, is when a homeowner believes they are getting a high-quality product and, in reality, they are getting a low-quality product that is not appropriate for their home and that will leave them frustrated and angry in just a couple of years.
Here’s the Key Question: What factors distinguish high-quality metal roofs from lower quality metal roofs?
It is critical for contractors and homeowners alike to understand the key answers to this question. In answering that, let’s take a look at 8 essential things that need to be thought about concerning metal roof specification.
When considering a metal roof panel regarding any of these things, no assumptions should be made. Again, we see significant downward pressure on price and quality in the metal roofing industry, both from domestic and overseas manufacturers.
Here are the Key Answers: 8 Factors that Determine Metal Roofing Quality
- Fasteners There are lots of things to know about how a metal roof will be fastened, and lots of places where corners can be cut. Are the fasteners exposed or concealed? What is the quality of the fastener? Are they from compatible metal for the roofing be installed? In what ways does how the roof is fastened allow for thermal movement of the metal panels?
- Base Metal Metal type specification is critical to project success. Galvanized steel, Galvalume steel, and aluminum are common. Exotic metals can include copper, zinc, and others. Based on the location of the project, what is the best metal? Things like salt and tropical environments, propensity for acid rain, extreme snow loads, and severe hail are all factors to think about. But, beyond choosing the type of metal, be aware that there are various grades of these metals. Not all galvanized or Galvalume steels are the same. Lower quality products have less zinc on them, and it is the zinc that provides for cut edge protection. Reduce the zinc, and performance is diminished dramatically. In particular, we have seen very low-quality metals being used in metal roofs produced overseas. We also see lower quality steels in the agricultural market often spilling over into residential applications.
- Coating There are two primary paint chemistries used on metal roofs today. They are named for the resin in the paint. Those are Polyester finishes and PVDF finishes. While there are upgraded versions of Polyesters available, their performance beyond about 7 years is very inferior to the PVDF coatings, leading to frustrated property owners. Additionally, some manufacturers play games with the thickness of the paint on their products. Paint costs have been going up significantly, so they have found that less paint allows them to produce a cheaper product, or increase their profits. These “low film” products, though, will erode much more quickly than industry standard finishes will. The other type of typical coating is an aggregate coating, and consumers must be made aware that the stones will wear away gradually over time and that these products can be more susceptible to mildew collection.
- Metal Thickness Metal thickness is largely a component of product design. While understanding the thickness of the metal is never a bad thing, it’s important to keep in mind that more heavily formed products will naturally be made out of thinner metals. This is due to manufacturing constraints in many cases, but it’s also because the forming of the metal builds strength into it.
- Panel Design The “style” of metal roofing goes beyond just aesthetics and fasteners when it comes to product selection. One other key component is whether the panels interlock with one another or just engage. Also, how do the trims work? Do they engage with the metal panels or just rest above or beneath them? Pay close attention to the valleys. Poorly engineered valleys clog with ice, snow, and tree debris, leading to significant roof failure in a few years.
- Warranty There are many things to consider when it comes to product warranties. Who is behind the warranty? Does the warranty cover actual product performance or just the coating? Is it both prorated and transferable? Warranties are legal contracts between the buyer and the seller – they are not indications of performance expectation. Be sure to understand exactly what warranty is being provided.
- Industry Certification The Metal Construction Association (MCA) administers North America’s only independent metal roofing certification program. Their program certifies the quality level of products. I highly recommend only getting involved with products that are MCA Certified Premium Quality.
- Installation I probably should have started with this problem. Proper installation is critical for all metal roof systems. I have always said that I will take an average-grade product that has been installed properly over the best product improperly installed any day! Make sure that you know who will be doing the installation of any metal roof, that they are expertly trained, and experienced.
Now, while the above are all critical things to think about, it’s essential to think about them in terms of the context of the structure upon which the roof will be installed. What do you want to accomplish with the new roof? Is there anything special about the shape of the structure or roof that places particular demands upon product selection, such as the flying gables I mentioned earlier?
As always, know that I am available to be your guide in understanding metal roofing. Feel free to email me whenever I can be of service.
Todd Miller has spent his entire career in the metal building products manufacturing industry. He is president of Isaiah Industries, an organization recognized as one of the world’s leading metal roofing manufacturers. Todd is currently Vice President of the MRA (Metal Roofing Association) and a Past Chair of MCA (Metal Construction Association). Through his website, he strives to raise the bar on standards and practices to provide property owners with the best possible products for successful roofing projects.
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