Weathering the Storm: How Metal Roofs Perform in Hurricanes and Severe Weather

In areas prone to hurricanes and other extreme weather events, having a reliable roof can be the difference between minor repairs and catastrophic damage. Among traditional roofing options, metal roofs stand out for their durability and reliability. According to FEMA P-2181, many metal roofing systems are rated to withstand winds of over 150 mph. This makes them an effective alternative to traditional roofing materials in mitigating storm damage.

In this post, we’ll explore how metal roofs can protect your property during hurricanes and other severe weather conditions.

Understanding Metal Roofs

Like most other products, you’ll have several choices for your metal roofing system. Each choice impacts cost, appearance, durability, and wind resistance. 

Aluminum: While aluminum products offer excellent rust resistance, especially in salty environments, the product is lightweight and more susceptible to blow-off during high wind events. As the frequency and severity of hurricanes increase, property owners have begun to place a higher emphasis on structural integrity over corrosion resistance. Resulting in an uptick in the use of zinc and GalvalumeⓇ substrates in hurricane zones.

Zinc: Galvanized substrates represent a longstanding workhorse for metal roofing panels in non-coastal applications. When working with zinc substrates, it’s important to understand that the level of zinc on the panel directly correlates to the expected service life and performance. 

G100 and G60 are two commonly used Galvanized substrates. These designations relate to the total zinc on both sides of the panel surfaces. G100 products contain 66% more protective zinc than a G60 substrate. 

While some suppliers continue to offer zinc substrates as their standard offering, others, like McElroy, have also added Galvalume products to their stocking programs to offer customers greater performance options. 

Galvalume: GalvalumeⓇ, invented by Bethlehem Steel in 1972, is a combination of 43.5% zinc, 55% aluminum, and 1.5% silicone.  Galvalume is the trademarked name for this product family, also called Zincalume.

This substrate composition combines zinc's sacrificial properties and aluminum's barrier protection.  Consequently, it delivers superior performance in almost all applications, but especially in marine environments. Check out our recent blog, which discusses why Galvalume continues to gain momentum in coastal applications. 

Once you determine your desired substrate, you’ll need to consider your panel type. You’ll find two main styles of metal roofing systems:

 Concealed fastened systems offer a sleek, modern look and minimize the risk of water infiltration since the steel panel isn’t pierced by a fastener during installation. Most folks refer to this panel family as standing seam roof systems. They are highly regarded as offering unparalleled durability and performance while requiring minimal maintenance.

Exposed fastened systems: In contrast, exposed fastened systems use fasteners that pierce the metal during installation to attach the metal panels to the substructure. These types of systems cost less than their concealed fastened counterparts; however, they can offer reduced watertight integrity. Additionally, panel lengths over 20’ may require fastener replacement during their 60-year life expectancy. 

Advantages of Metal Roofs in Hurricanes

Metal roofs offer significant advantages in hurricane-prone areas due to their durability and resilience.

1. Structural Integrity

Metal roofs maintain their structural integrity over time, unlike asphalt shingles, which can become brittle and lose wind resistance with age. This means metal roofing stays strong even after decades of wear and tear.

2. Wind Resistance

Metal roofs can withstand winds up to 150 mph or more, making them an excellent choice for areas subject to hurricanes and extreme weather. One reason for this is the ability to customize metal roofing systems to suit specific building needs.

•         Standing seam panels, for instance, are often built with thicker gauge metal and narrower widths for enhanced stability. Using continuous clips and tightening clip spacing at the roof’s corners further improves performance.
•         Exposed fastened panels also benefit from techniques such as tighter fastener spacing, which helps to secure the roof even in extreme winds.

3. Impact Resistance

Metal roofs provide superior impact resistance. Flying debris can easily damage or penetrate materials like shingles and membrane roofs, but metal roofing routinely holds up against these impacts. Many metal roofing systems undergo rigorous impact testing, such as TAS-201, where a 2x4 is fired at the panels to ensure they can withstand high-force impacts.

Additionally, many metal roofs have a Class 4 rating under the UL 2218 Impact Resistance Test — the highest rating available — indicating superior resistance to hail and other flying debris.

4. Resistance to Wind-Driven Rain

Beyond structural damage, hurricanes often bring heavy, wind-driven rain, which can lead to leaks. Metal roofs are designed to handle this, with certain panels tested to withstand wind-driven rain at speeds up to 110 mph. This capability minimizes water infiltration, helping to protect the interior of your home even during intense storms.

Advantages of Metal Roofs in Other Harsh Weather Conditions

Metal roofs perform well in various harsh conditions beyond hurricanes, offering resilience against wildfires, hail, and heavy snow.

1. Wildfires

Metal roofing materials are non-combustible and typically have a Class A fire resistance rating — the highest available. Unlike asphalt shingles, which can break apart and contribute to the spread of flames by blowing embers, metal roofs do not ignite or fuel the spread of flames.

This makes them an ideal choice for wildfire-prone regions. While asphalt shingles can melt or warp under intense heat, metal roofs maintain their structure, acting as a reliable barrier against flames.

2. Hail Resistance

Metal roofs are also well-suited for hail-prone areas due to their strong impact resistance. Most metal roofing systems have a Class 4 rating for impact resistance, meaning they can withstand significant hail impact without compromising their structural integrity.

While hail may cause minor cosmetic dents, it rarely affects the roof's overall performance or safety. In contrast, asphalt shingles often crack, split, or lose protective granules during hailstorms, resulting in costly repairs or replacements.

3. Snow and Ice Performance

Metal roofs also excel in snowy and icy climates. Their smooth surfaces allow snow to slide off easily, reducing the risk of excessive snow buildup. Many building owners add snow retention systems to metal roofing projects to minimize the risk of injury from snow sliding off the roof.

Likewise, metal roofs offer superior thermal conductivity, which helps them melt snow more quickly. This reduces the likelihood of ice dams — a common issue with shingles. This quality helps prevent water damage to the roof and underlying structures. 

Preparing for Severe Weather

To prepare your metal roof for severe weather, start with a thorough inspection. Check for any existing damage, such as dents, rust, or loose panels and trim. Address these issues before harsh weather arrives. In extreme cases, you may want to hire a professional inspector for a more detailed evaluation.

Ensure all screws and fasteners are secure and in good condition, and check that the roof system is properly attached to the sub-framing. For maintenance, clean gutters and downspouts to facilitate water drainage. Trim any overhanging branches, and consider adding extra bracing or hurricane clips. Also, secure outdoor items to prevent damage during storms​ and high winds.

Post-Storm Efforts

After a storm, follow these steps to assess and protect your metal roof:

• Conduct a visual inspection from the ground, checking for loose or missing panels and trim. Binoculars or drones can help you get a better view.
• Check inside your home for leaks or signs of water intrusion. Take immediate steps to collect the water and protect your items if needed.
• Remove any debris or branches from the roof area, and ensure gutters are clear to allow proper drainage.
• Document any damage by taking photos and videos for your insurance claim. Contact your insurance company first, then seek contractor referrals from trusted friends and neighbors to ensure reliable repairs.

Resources with McElroy Metal

Metal roofs offer exceptional durability and longevity, providing top-tier resistance to wind, impact, and fire. They reduce maintenance costs while giving your home unrivaled protection against hurricanes and extreme weather conditions.

For installation help, use our Find a Contractor tool. For more tips on disaster preparation, visit the IBHS Home Disaster Guides for hurricane and wildfire preparedness.