Metal Roofing Myths: Busted!

Metal roofing myths are everywhere, but it's time to separate fact from fiction. At The Roofing Store in New Zealand, we aim to clarify the most common misconceptions about metal roofs.

 
 

Myth #1: Metal Roofs Attract Lightning

Many believe metal roofs attract lightning, but this isn't true. The misconception stems from the fact that lightning rods, often made of metal, are used to channel lightning safely to the ground. However, the material of your roof doesn't influence the likelihood of a lightning strike.

The likelihood of a lightning strike is determined by factors such as:

  • Topography: Higher ground, like hills or mountains, is more prone to lightning.

  • Building Size: Larger buildings have a higher chance of being struck due to their size.

  • Proximity to Other Structures: Smaller buildings near taller ones are less likely to be hit.

  • Thunderstorm Frequency: Areas with frequent thunderstorms have higher risks.

Metal roofs are actually safer during storms because they are non-combustible, meaning they won't catch fire if struck by lightning.

Myth #2: Metal Roofs Are Noisy

It's a common misconception that metal roofs are noisy during rain or hail. While it's true that some metal roofing systems can be noisier under certain conditions, modern metal roofs are designed to minimize noise. Factors that influence noise levels include:

  • Roof Deck: A solid roof deck with sheathing and insulation acts as a buffer to reduce noise.

  • Thermal Movement: Proper installation allowing for thermal expansion and contraction can prevent noise issues.

  • Insulation: Adding insulation can significantly dampen sound, making metal roofs no louder than other types.

  • Installation Expertise: Hiring experienced installers ensures the roof is properly fitted, reducing potential noise.

For those who enjoy the sound of rain, installation methods can be adjusted to meet your preference.

Myth #3: Metal Roofs Rust Easily

Not all metal roofs rust. Advanced materials and coatings are designed to prevent rust for many years. Here’s a look at some common materials:

  • Galvalume®: Combines steel, aluminum, and zinc, providing excellent corrosion resistance. It has self-healing properties that regular galvanized steel lacks.

  • Aluminum: Does not develop red rust and is highly resistant to corrosion, making it ideal for coastal areas.

  • Copper: Develops a protective patina over time instead of rusting.

  • Zinc: Forms a protective layer called zinc carbonate when exposed to the elements, preventing rust.

  • Stainless Steel: Contains chromium, which makes it resistant to rust and corrosion.

In addition to these materials, paint systems applied to metal roofing also prevent rust and corrosion. Many manufacturers offer warranties for added peace of mind.

Myth #4: Metal Roofs Dent Easily

Contrary to popular belief, metal roofing is highly resistant to denting and puncturing. Concerns about hail damage are largely unfounded. Here’s why:

  • Impact Resistance: Metal roofing is tested using the Standard for Impact Resistance of Prepared Roof Covering Materials (UL 2218). This testing rates materials from Class 1 to Class 4, with Class 4 being the most resistant.

  • Design Features: Metal roofs with rib rollers or striations can hide minor dents, making them less noticeable.

Even in areas prone to hail, metal roofs stand up well to the elements, and most home insurance policies offer hail damage coverage options.

Myth #5: Metal Roofs Retain Heat

While metal in the sun does hold heat, modern metal roofing technology has overcome this issue with cool metal roofs. These roofs are designed with high Solar Reflective Index (SRI) ratings:

  • Solar Reflectance: Measures how much solar energy is reflected by the roof surface. Higher values indicate better reflectance.

  • Emissivity: Measures how efficiently a material emits absorbed heat. Higher values indicate better performance.

  • SRI: Combines solar reflectance and emissivity to provide an overall measure of a material's ability to stay cool in the sun.

Cool metal roofs reflect solar energy and emit absorbed heat efficiently, keeping buildings cooler in the summer. They are energy-efficient, eco-friendly, and available in various colors and finishes.

Conclusion

Understanding the truth about metal roofing can help you make informed decisions. Metal roofs don’t attract lightning, aren’t excessively noisy, resist rust, are durable against dents, and help manage heat efficiently. For more information and personalized advice, contact The Roofing Store in NZ today and speak with our metal roofing experts!