When deciding what material to purchase for your metal roof in Florida, you may have come across various options like steel, copper, aluminum, galvanized, and Galvalume. So what’s the difference, and how do you know which one is right for you?
Weighing the pros and cons of Galvalume and galvanized roofing can certainly be confusing. And since installing a new roof can already be a costly and stressful process, we’re eager to offer our expertise. We’ve created a helpful guide to walk you through choosing the right roofing material for your needs.
Why choose a metal roof in Florida?
Overall, the main advantage of using a metal roofing material in Florida and coastal regions is its ability to withstand harsh weather conditions, including wind, rain, and saltwater corrosion. However, each type of metal roofing material has its own unique advantages, and choosing the right material depends on factors such as budget, aesthetics, and performance requirements. A qualified manufacturer and supplier of different metal roofing types and materials can provide valuable advice for your particular project.
Galvalume vs Galvanized vs Aluminum
Here are three popular types of metal roofing materials in use today:
Galvanized Steel Roofing
Galvanized steel is a type of steel that has been coated with a layer of zinc to protect it from corrosion. The process of galvanization involves immersing the steel in a bath of molten zinc or applying a zinc coating through electroplating. The zinc coating acts as a sacrificial layer, meaning that it corrodes before the underlying steel, providing protection against rust and extending the lifespan of the steel. Galvanized steel is relatively low in cost compared to other corrosion-resistant materials, but may not last as long before showing signs of corrosion.
Galvalume Roofing
Galvalume is a steel-based roof coating type that includes aluminum, zinc, and silicon that is up to twice as resistant to corrosion as galvanized steel. Invented by Bethlehem Steel Construction Company in the early 1970s, Galvalume coating is made by hot-dipping the metals onto steel coils to make them adhere to the material. The coating can remain with a plain mill finish or painted in a variety of colors. As one of the most popular roofing materials on the market today, it’s impressively durable. It is a low-maintenance material that will last for at least 40 years, providing significant savings throughout its lifetime.
Aluminum Roofing
While Galvalume provides good corrosion resistance due to its zinc-aluminum alloy coating, aluminum roofing offers even greater resistance to corrosion. Aluminum is inherently resistant to rust and corrosion, making it an excellent choice for areas with high moisture or salt exposure, such as coastal regions. Both aluminum roofing and Galvalume have long lifespans, but aluminum is generally considered to have superior longevity.
Applications
Where Should Galvalume Roofing Be Used?
The main purpose of a Galvalume coating is to protect steel from oxidizing (rusting), which compromises the integrity of the material. It may be installed on a wall, building trim, or as an accent, especially in climates subject to hurricanes, humidity, extreme heat, or high rainfall or snowfall. Thanks to its corrosion-resistant properties, Galvalume is ideal for humid and hot environments, commercial buildings, residential homes, storage units, and more, making it an affordable, low maintenance roofing material choice in many areas of Florida.
Where Should Aluminum Roofing Be Used?
Aluminum is preferred to Galvanized or Galvalume steel in coastal areas, as the elemental metal is more resistant to saltwater-induced corrosion and rusting. Galvalume’s zinc-aluminum coating cannot withstand prolonged exposure to significant volumes of salt commonly found in the air of coastal areas. Saltwater is highly corrosive, which can quickly degrade Galvalume roofing on properties along the coastline, near large bays, surf breaks, and marshes. Aluminum is also highly malleable and can be easily formed into various shapes, profiles, and designs that gives architects and homeowners more flexibility in creating customized roof designs. Galvalume, being a steel product, has some limitations in terms of formability and design options.
Where Should Galvanized Steel Roofing Be Used?
Galvanized metal roofing is better suited for dry climates, free of pooling water and salt air environments which limits its broad application in Florida. Galvanized or pre-galvanized materials or insulated metal panels are a preferred choice for lower value applications such as outbuildings or barns. As a rule, Galvalume is not ideal for buildings used to house or enclose livestock, as its aluminum and zinc coating reacts with the ammonia from livestock manure. Animal waste breaks down into ammonia gas, creating a highly aggressive and corrosive environment that can damage metal roofing and walls. Once the metal loses its protective coating, it will rust and corrode within a short time. If you choose to use this material for structures used for animal confinement, they must have adequate ventilation to reduce ammonia gas concentration and its corrosive effect on Galvalume.
What Does Self-Healing Mean for Galvalume?
Most steel roofing materials end up having some “edge creep” near the edges where the panel was cut. Fortunately, Galvalume is “self-healing,” meaning it eventually stops creeping and won’t spread rust all over the panel. But galvanized steel is not self-healing—the edge creep rusting will only worsen over time. The combined self-healing and rust-resisting properties of zinc and aluminum ensure that the material remains structurally sound despite its exposed edges. Eliminate the risk of edge creep through hemming or touching up the bare spots with paint.
Metal Roofing Wear
Although the wear of metal roofing is vastly superior asphalt, over time it can exhibit some wear characteristics that you should know about.
- Oil Canning
Oil canning refers to the visible waviness or distortion on the flat surface of a Galvalume, painted or aluminum metal panel. It is innate in light-gauge, cold-formed metal products, particularly those with wide flat areas. This issue is only cosmetic and won’t impact the roof’s strength, durability, performance, or lifespan. Oil canning doesn’t indicate the quality or structural issues with the roof, so it’s not considered a valid warranty claim as it won’t affect material performance. However, it can impact the overall appearance of the structure. - Scuff Risk
On painted or unpainted metal materials including Gavalume and aluminum, it’s important to know that its coating can scuff, leaving an exposed portion of the metal panel that ages and weathers faster due to the lack of a protective layer. While many prefer the performance of Kynar painted panels, it is a softer finish than our standard WeatherXL paint and can be more easily damaged by foot traffic and environmental wear factors. Since you cannot fix a scraped surface, you may have to replace the entire section. Scuffing can also occur after the material gets dented, so avoid surface damage by limiting foot traffic and minimizing pressure or weight on the panels. If you need to place a ladder against the roof, do so in a way that it won’t scratch the surface. - Galvalume May Not Pair with Certain Materials
Although Galvalume is highly durable, using it alongside other construction materials can speed up the degradation process. When installed directly on bricks, concrete, treated lumber, or other metals like iron and copper, this material may corrode in response to an electrolyte, like water. For this reason, it’s also important to use a compatible screw material on any metal roof. Plus, mortar and concrete are highly alkaline, making them corrosive to Galvalume. If left unchecked, rust and corrosion can cause the roofing structure to fail. When the design requires Galvalume with the materials mentioned above, take precautions to minimize the risk of corrosion.
Which Is Thicker—Galvanized or Galvalume?
Galvalume and galvanized steel are both made through a hot-dipping technique and have a similar thickness, which is usually around 1 millimeter. This thickness may vary slightly from one material to the next, but if the Galvalume and galvanized steel coating are of the same thickness, the Galvalume coating will usually last longer than the galvanized coating.
What Roofing Material Lasts the Longest?
As we’ve mentioned already, Galvalume tends to last almost twice as long as galvanized steel before it shows any signs of wear. This is mainly due to the aluminum that is added to the coating to prevent oxidation. Both Galvalume and aluminum roofing have long lifespans, but aluminum is generally considered to have superior longevity. Aluminum roofs can last for many decades without significant degradation, whereas Galvalume roofs typically have a slightly shorter lifespan. For the greatest lifespan, select stainless steel or aluminum roofing materials.
What Has a Better Warranty?
Virtually all aluminum and most Galvalume roofing materials come with a warranty because they’re known for being durable and long-lasting. However, many galvanized materials do not have a warranty since they can be unpredictable and unreliable, especially once they begin to rust.
What Material is Most Affordable?
Because galvanized and Galvalume steel are made in a similar fashion, they’re sold at a similar price, though some lower grades of galvanized steel are available for less expense. Aluminum roofing is a premium product that offers higher performance and lifetime, but also a higher cost. Metal roofing is often more expensive than asphalt shingles, but the long-lasting nature of the products means they are usually more cost-effective overall and save the homeowner money long term.
As we outline in our metal roofing cost guide, other factors also affect project pricing. Underlayment, complexity, and scope are some considerations that can weigh on the total cost. If you want to know how Galvalume compares to other roofing materials, request a quote from different roofers.
The Bottom Line
Here are the differences and advantages of each roofing material in Florida and coastal regions:
- Galvanized steel: Galvanized steel is coated with a layer of zinc to protect against corrosion. However in Florida, humidity and salt air can accelerate corrosion on galvanized steel so it’s not recommended for long-term durability in residential applications. Its advantages include affordability, ease of installation and a classic look.
- Galvalume: Galvalume is a popular choice for many Florida regions because of its enhanced durability and ability to withstand corrosion better than galvanized steel. In addition, Galvalume roofing is generally less expensive than aluminum roofing. If cost is a primary consideration, Galvalume may be a more budget-friendly option.
- Aluminum: Aluminum is a premium lightweight metal that is inherently resistant to rust and corrosion. It is the preferred choice for coastal regions due to its higher resistance to saltwater corrosion and superior longevity. Other advantages include durability, low maintenance and higher energy efficiency due to its reflective surface.
Ultimately, a choice between Aluminum roofing vs Galvalume depends on factors such as the specific application, budget, desired aesthetics, and environmental conditions. Both materials offer corrosion resistance and durability, but aluminum roofing excels in terms of superior corrosion resistance, lighter weight, and enhanced thermal performance.
We can help
Choosing the right metal roofing materials can be overwhelming, but now that you know more about these types of roofs, you’re better equipped to handle the big task of installing a new one.
Does Galvalume or Aluminum sound like the right choice for your next project? Contact 1st Coast Metal Roofing Supply to order your high-quality materials. We’re happy to answer any of your questions about metal roofs and offer help you decide if you’re still comparing Galvalume vs galvanized or aluminum roofs. Get in touch with us today for a free quote.
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About 1st Coast Metal Roofing Supply
Protect your home from Florida’s extreme weather conditions with durable and reliable metal roofing solutions from 1st Coast Metal Roofing Supply. As the leading metal roofing manufacturer and supply company based in Florida, we offer a wide range of high-quality roofing materials that are designed to withstand hurricane-force winds, tropical rainfalls, and the harsh UV effects of intense sunlight. With our expert guidance and exceptional customer service, you can trust us to provide you with a roof that not only looks great but also lasts for years to come.
