As a Metal Roofing Contractor or Manufacturer. You have heard the terms Galvalume and Galvanized thrown around.
Galvalume is a type of metal that has a steel core, coated with a mixture of aluminum and zinc for added durability, while Galvanized metal is simply steel coated in zinc.
Clarifying these terms is key when deciding which roofing material to choose for your client.
COSASTEEL is familiar with the material selection of roofing manufacturers. We supply you with galvanized steel coils and galvalume steel coils.
Galvalume and Galvanized
Galvalume and Galvanized steel are both popular materials used in construction and manufacturing due to their corrosion-resistant properties. Here are some key similarities between the two:
Base Material: Both Galvalume and Galvanized steel start with a base of carbon steel, which provides strength and durability.
Corrosion Resistance: Both coatings are designed to protect the steel from rust and corrosion, extending the life of the material in various environments.
Application Methods: Both Galvalume and Galvanized coatings are typically applied through a hot-dipping process, where the steel is submerged in a molten bath of the respective coating material.
Uses: Both materials are widely used in similar applications, such as roofing, siding.
Composition and Coating
Galvalume
1. Composition:
– Base Material: Also typically made from carbon steel.
– Coating: Coated with an alloy consisting of approximately 55% aluminum, 43.4% zinc, and 1.6% silicon.
2. Coating Properties:
– The aluminum in the coating provides a barrier protection similar to aluminum foil, while the zinc offers galvanic protection.
– The silicon helps the coating adhere to the steel and improves its durability.
– This combination results in a coating that offers superior corrosion resistance compared to galvanized steel, especially in harsh environments.
– The appearance is generally more uniform and less spangled than galvanized steel.
Galvanized
1. Composition:
– Base Material: Typically made from carbon steel.
– Coating: Coated with a layer of pure zinc through a process called hot-dip galvanizing.
2. Coating Properties:
– The zinc coating provides a physical barrier and acts as a sacrificial anode to protect the steel from corrosion.
– The thickness of the zinc coating can vary, which affects the level of protection and the lifespan of the material.
– Typically has a spangled appearance due to the crystallization of the zinc coating.
Corrosion Resistance
Curious about how Galvalume and Galvanized metal stack up against each other when it comes to corrosion resistance? Let’s dive into the details!
Galvalume
Performance in Different Environments:
Galvalume is a real champ in coastal areas or places with high humidity. The combination of zinc and aluminum in Galvalume makes it highly effective against rust.
Imagine the zinc as the bouncer and aluminum as the protective bubble. Together, they keep corrosion at bay!
Long-term Durability:
Galvalume metal roofs tend to last longer because of this enhanced corrosion resistance. You might be looking at two to four times better corrosion resistance than galvanized metal. This makes it a solid choice for long-lasting durability.
Galvanized
Performance in Different Environments:
Now, let’s chat about galvanized metal. This type uses a zinc coating to protect against rust. Zinc acts like a sacrificial anode, meaning it’ll corrode first before the underlying steel does, offering a decent level of protection.
Galvanized metal is reliable, especially in less harsh environments.
Long-term Durability:
When it comes to lasting power, galvanized metal does well. However, its performance dips in salty, humid, or intense weather conditions compared to Galvalume. It’s great for general use but might not match Galvalume in the long haul.
So, whether you’re near the coast or just want something durable, understanding these differences will help you make an informed choice!
Coating Weight
Galvalume
The coating weight for Galvalume is typically measured in grams per square meter (g/m²). Common coating weights range from AZ50 to AZ150, where AZ50 means 50 grams per square meter and AZ150 means 150 grams per square meter.
Galvanized
The coating weight for galvanized steel is also measured in ounces per square foot (oz/ft²). Common coating weights include G30, G60, and G90, where G90 means 90 oz/ft².
The larger the zinc weight number, the better the corrosion resistance.
Aesthetic and Surface Appearance
Galvalume
Visual characteristics
Galvalume roofs have a smooth, matte finish. The coating is a mix of aluminum, zinc, and silicon. This gives the surface a less shiny appearance, which many people find modern and sleek.
Suitability for visible applications
If you want a clean, contemporary look, Galvalume is a good choice. It doesn’t have the bright shine of galvanized metal, so it blends well with many architectural styles. It’s popular for sleek, minimalist designs.
Galvanized
There are 2 options for the surface finish of galvanized:
- Regular Spangle
- Minimized Spangle
Visual characteristics
Galvanized roofs start with a bright, shiny look. That’s because of their pure zinc coating. Over time, this shine fades to a matte gray patina, giving it a rougher appearance.
Suitability for visible applications
Galvanized metal works well if you like a more industrial or rustic look. It stands out more due to its initial shine. Even after it dulls, it retains a unique, textured appearance that many find appealing for traditional or rugged designs.
Applications and Case
A. Galvalume
1. Common Industries and Uses
Galvalume is widely used in construction and roofing due to its strong resistance to corrosion. You often see it in industrial buildings, agricultural facilities, and residential homes. It is also popular for making outdoor structures because it withstands harsh weather.
2. Specific Examples
- Roofing Panels:
- Usage: Often used in both residential and commercial roofing.
- Reason: Combines durability and aesthetic appeal.
- Outdoor Sheds:
- Usage: Perfect for garden sheds or storage units.
- Reason: Excellent weather resistance.
B. Galvanized
1. Common Industries and Uses
Galvanized steel is mainly used in industries needing strong, formable materials. Think automotive, construction, and appliance manufacturing. It’s especially popular for making pipes, fences, and wire mesh due to its rust-resistant properties.
2. Specific Examples
- Automotive Parts:
- Usage: Lots of smaller car parts are made with galvanized steel.
- Reason: High malleability allows for intricate shapes.
- Fencing and Pipes:
- Usage: Often used for exterior fencing and water pipes.
- Reason: Provides a durable and rust-resistant barrier.
Both Galvalume and galvanized steel have unique advantages tailored to different use cases. Whether you’re building a robust roof or crafting durable car parts, these materials offer reliable performance.
Advantages and Disadvantages
Galvalume
Pros
- Durability: Galvalume is known for its long lifespan. It can outlast galvanized steel, especially in harsh climates like coastal areas.
- Corrosion Resistance: This material offers excellent resistance to rust and corrosion due to its aluminum and zinc coating.
- Heat Reflectivity: Galvalume has excellent heat reflectivity, making it energy-efficient for roofing applications by reducing cooling costs.
Cons
- Not for Animal Structures: You shouldn’t use Galvalume in buildings that house animals like horses or cows. The coating can react with animal waste, leading to quicker degradation.
- Looks: It has a matte finish, which might not be as visually appealing if you prefer a shinier surface.
- Less Effective in Alkaline Environments: Galvalume is not as effective in environments with high pH levels or in areas exposed to concrete or mortar.
- Repair Complexity: Repairing scratches or damages on Galvalume can be more challenging compared to galvanized steel.
Galvanized
Pros
- Appearance: Galvanized steel has a bright, shiny surface, making it visually appealing if you like a glossy look.
- Versatility: It can be used in a variety of environments, especially dry ones with low air pollution.
- Tradition: This material has been widely used for years, making it a trusted option for many builders.
- Ease of Repair: Scratches and damages can be easily repaired with zinc-rich paint or sprays.
- Weldability: Galvanized steel is generally easier to weld than Galvalume, making it suitable for various construction applications.
Cons
- Less Durable: Galvanized steel generally has a shorter lifespan compared to Galvalume. It’s prone to rust and corrosion in humid and coastal environments.
- Water Pooling: It doesn’t fare well in areas where water tends to pool, as this can expedite rusting.
- Heat Retention: Galvanized steel retains more heat, making it less energy-efficient for roofing applications.
Conclusion
Let’s wrap things up by looking at the key differences. Here’s a quick summary:
- Corrosion Resistance: Galvalume shines with its aluminum-zinc coating, offering superior protection against rust. Galvanized metal, with its zinc coating, provides good corrosion resistance but not as effective as Galvalume.
- Longevity: Because of its excellent rust resistance, Galvalume generally lasts longer. It’s a smart choice if you’re looking for something durable.