Choosing a metal roof for your building doesn’t end there; you must also decide on the type of metal roof you want. Galvanized steel, aluminum, and copper, are some of the metal materials property owners use for their buildings.
People use galvanized steel for a lot of roofing applications. However, there are several things to consider before deciding on a galvanized metal roof. This step is critical, as it will influence your roof’s performance. In this piece, we will discuss the details of a galvanized roof and the reasons why you should or shouldn’t go for it.
What Is Galvanized Steel?
Out of all the types of steel available on the market, galvanized steel is a very popular option—one of the most popular, in fact. Manufacturers produce it by coating steel with zinc. The application of zinc protects the inner layer of steel from corrosive factors. This protection extends its lifespan, resulting in a premium-quality and long-lasting metal.
This type of metal is versatile, and as a result, people use it for different projects and industries, including construction, agriculture, and automotive. Some examples of what people use galvanized steel for are construction materials, pipes, phone wires, and tubing.
Using galvanized coils and sheets for roofing was a common practice before Galvume was introduced to the metal roofing industry. In the early 2000s, more than 90% of the industry started using Galvalume substrates instead of galvanized substrates. This switch happened because of its superior resistance to corrosion and its exceptional durability.
It is common practice for people to refer to galvanized metal sheets or coils by their coating weight name.
Applications of Galvanized Steel Metal
Galvanized steel is used almost everywhere, from water pipes to cars to nuts and bolts. A very common application is modern steel-frame structures. People also use it for walkways, staircases, ladders, and others.
Below are some of the industries where people apply galvanized metals:
- Construction industry: It is a popular choice in the construction industry due to its durability and aesthetic appeal. People use it for commercial and residential buildings. Galvanized steel gives buildings a shine that gives them a modern look, making it prevalent in contemporary architectural designs. Aside from using it for extensive structures, they use it for fencing, rails, poles, and gutters, to mention a few.
- Solar industry: Hot-dipped galvanized steels are commonly used in solar projects because of their corrosion resistance. Aside from that, it is a popular choice because it is environmentally friendly, as it doesn’t have any emissions and can last for decades, even without maintenance.
- Telecommunications industry: Phone lines are pretty high and, as a result, difficult to reach. This makes them a bit challenging to maintain. Using hot-galvanized steel on equipment boxes and phone wiring reduces the need for maintenance and the chances of damage.
- Automotive industry: Although zinc-coated car bodywork was limited to luxury automobiles until the 1980s, it is now a standard in the auto industry. Galvanized steel’s resistance to rust helps manufacturers give their customers anti-rust warranties. Hence, they use galvanized steel to make the ‘body-in-white’ of cars, which constitutes about 80% of the body.
Advantages and Disadvantages of Galvanized Steel
Advantages
- Malleability: Galvanized steel is a malleable metal. It can bend and form more easily than other metal types. For this reason, manufacturers often use them in stamped vent flashings or stamped metal shingles. This property can also make roll-forming galvanized panels slightly neater and allow for more uncomplicated cutting and shaping at installation.
- Rust resistance: Steel is highly rust-prone because of its iron elements. However, galvanized steel is resistant to rust due to its zinc coating. Zinc acts as a cushion that protects the steel from the action of oxygen or moisture.
- Longer lifespan: It has a life expectancy of over 50 years in a moderate environment. However, when you expose it to water a lot, it can last for as long as 20 years or a little more. It also doesn’t require maintenance.
- Low initial investment: Unlike most treated steels, galvanized steel has a low initial cost. Additionally, it is ready to use as soon as it arrives. It doesn’t need any additional surface preparations, coatings, inspections, or other processes, which helps to save money that property owners could have spent on those things.
- Suitable for animal sheds: One of galvanized steel’s most outstanding benefits is its suitability for the construction of animal sheds. Unlike Galvalume, which is not ideal for building animal shelters. The Galvalume reacts with the ammonia gas from the animals’ wastes over time. This reaction disintegrates the Galvalume coating and damages the metal. Despite the galvanized steel’s suitability for animal sheds, it is best to consult the manufacturer before putting one on the building for your animals. They might have advice that will be beneficial for your design.
Disadvantages
- Lack of substrate warranties: A significant disadvantage of this metal type is that the substrate has no warranty. Many manufacturers do not give warranties on galvanized products, which is why most homeowners go for Galvume instead.
- Limited protection: Galvanized steel is protected from corrosion thanks to its zinc coating. However, this protection is limited. The zinc will wear off after a while and leave the steel exposed to corrosive elements. In addition, this metal is generally less protected from corrosive elements than some metals, like stainless steel.
- Visually unattractive: Not everyone finds this type of metal aesthetically appealing. The zinc coating gives the metal a dull look that some find unappealing. Also, the zinc coating starts to come off after some time, causing red rust, which isn’t an appealing sight.
- Not readily available: Galvanized steel roofing products are hard to come by in the market. This is because many manufacturers have hopped on the Galvalume train because it is more durable than galvanized steel, and property owners find it more beneficial. However, you will still find some areas in the US that use galvanized steel products more.
- Unsuitable for coastal environments: Steel’s zinc coating cannot withstand coastal environments and the conditions associated with them. When galvanized steel comes into contact with saltwater in the atmosphere, the zinc coating starts to break down, shortening its lifespan.
Conclusion
Several factors, including the type of coating used, the coating’s thickness, and the conditions you expose it to, influence the lifespan of galvanized steel. When you use and maintain galvanized steel properly, the coating will take longer to wear off, extending its lifespan and saving you some money.
However, you should also be aware that the choice of roofing contractor significantly impacts the success of your metal roof. When you use a professional who knows their onions, they can guide you on your choice of roofing material and give recommendations based on several factors, like your desire, environment, and budget.
Frequently Asked Questions
How much does galvanized metal roofing cost?
Galvanized metal roofing can cost between $4.50 and $17 per square foot or between $400 and $900 per square foot.
Can galvanized steel rust?
Although it takes a long time for galvanized steel to rust, it eventually will. The zinc coating on the steel protects it from corrosive elements like water and oxygen. However, after a long time, the protective coating starts to wear off, and this is when rusting starts.
Can you paint galvanized steel?
Although hot dip galvanizing is cost-effective and sufficient to keep steel protected against corrosion for a long time, you can still paint your galvanized steel. There are several reasons why people would want to paint their galvanized steel. They include the addition of color for aesthetics and safety purposes, among others.
How can you tell if a metal is galvanized?
One way to spot galvanized metal is to note its pattern. If you look at the metal and it has a spangle pattern, that means it is galvanized. A spangle pattern has the appearance of gray sponge-painted metal, with lighter and darker spots similar to those of a sponge-painted wall.
How long does galvanized steel last?
Hot-dip galvanized steel can last for as long as 50 years in normal environments. However, in corrosive environments, such as coastal ones, it has a life expectancy of about 25 years. The actual lifespan of galvanized steel depends on the environmental conditions.
