Metal Roofs: All About Metal Alloys
May 21, 2021 | By Mike Gonet | Filed under: Blog, Metal Roofing, Research
Understanding Base Metals to Make the Best Roof Choice for Your Home
You may think of metal roofs as all the same, but just as there is a wide variety of designs, styles and colors to choose from, the metal roofing category itself actually encompasses a range of different alloy types–all of which have different characteristics, costs and advantages. That’s why it’s important to understand your options, and what to expect when it comes to choosing a new metal roof for your home. Here’s an overview of the four main types of metal roofing materials to help guide you on how to make the best choice for your home.
1. Steel for Metal Roofs
Steel is a strong, durable, but NOT a choice for residential applications. Why? Because it rusts. Steel is also more affordable, so unsuspecting homeowners fall into the trap of price and buy a roof that doesn’t belong on a house. Thanks to advancements in quality coating systems, steel comes in a huge array of different high-performance colors. However, once the steel roof is cut the coating is gone and a raw edge of steel is exposed. That begins the rusting process immediately.
Yes, steel roofs can mimic copper, zinc and other material types such as clay tile, slate and shake. But when it comes to architectural residential metal roofs, steel is the wrong choice.
Stone coated steel is another option for those who want the look of shake. But once again, the stone coated products don’t hold up as advertised. They lose their granules much like an asphalt shingle so one ends up with shiny steel “bald spots” on the roof that begin to rust almost the first wet day. When it comes to architectural metal, lifetime roofs consider the following alternatives.
2. Copper for Metal Roofs
Copper roofing is an extremely long-lasting and beautiful material, and it carries a high price tag to match. Homeowners need to understand that copper will continue to change over time, and how a copper roof looks today will not be how it looks years from now. That evolution is one of the reasons why it is so prized for architectural roofing systems where a one-of-a-kind, custom look is desired. Copper also needs to be separated from other metals as its natural compounds may speed up the corrosion of the metal it comes in contact with. For this reason, it’s important to work with a knowledgeable installer who has experience working with copper. Using copper for unique roof designs, accents or special highlights is an excellent option for how to incorporate the beauty of copper without the high expense of using it for an entire roof.
3. Aluminum for Metal Roofs
Aluminum resists rust and salt corrosion very well, making it suitable for all climates including coastal areas. It has natural protection abilities: when it is subjected to oxygen, aluminum creates a layer of aluminum oxide that seals the metal’s inner layer to protect it from future corrosion and gives it long-lasting protection. It is typically more expensive – priced between steel and copper. And depending on how it is manufactured, aluminum panels have a high strength-to-weight ratio. Because of the way aluminum patinas it is often treated with paint and protective coatings. The most energy-efficient of all the options, these roofs last for 100 years plus keep a house cooler in the summer and slightly warmer in the winter.
4. Zinc for Metal Roofs
Zinc is not as common as other types of metal roofs, but it can be a great architectural feature given it can be easily formed and manipulated as a softer, less rigid metal. That makes it popular for unique roof designs, and it can last for centuries. The cost of zinc is more than copper. Zinc will react to its environment and change its appearance over time if left bare. One of the most amazing properties of zinc is its patina that can heal scratches over time. However, one of the drawbacks is that it is also subject to chalking effects, especially where water collects and flows. So it is often sealed with a protective coating.
Learn More About Metal Roofing
For more information about metal types, how to choose a quality metal roof designed to last for a lifetime, and additional details about metal roofing properties and performance capabilities, download a free copy of our Buyer’s Guide.
Thinking about sticking with asphalt? Download our Aluminum vs. Asphalt Shingles one-sheet.