Metal roofs can be a valuable asset to have if you live in hurricane country. While metal roofs can be somewhat more costly to install than asphalt shingled roofs, and may require longer installation times, they withstand wind and elements significantly better than other roofing materials. Metal roofs also feature several eco-friendly and energy saving benefits, making them one of the best roofing choices for homeowners along the Eastern Seaboard, Southeast, and Gulf Coast.
Are Metal Roofs Really Resistant to High Winds?
The wind-resistant qualities of a metal roof are what makes them stand out above other roofing materials, particularly in hurricane country. Category 4 hurricanes have winds ranging from 130 to 156mph while category three hurricanes are rated at 111-129 mph. Immediately after installation, most metal roofs feature a wind resistance rating of up to 140mph and come with a wind speed warranty.
By contrast, standard 3-tab asphalt shingles can withstand 60 mph winds, but there are a few very specialized—often prohibitively expensive—asphalt tiles that can withstand wind speeds up to 130 mph. Unfortunately, few asphalt installations come with a wind speed warranty. In hurricane-prone areas, metal roofs are the standout choice.
What Makes a Metal Roof So Wind-Resistant?
Metal roofs are capable of resisting wind primarily because they are constructed of wide strips of single pieces of metal. Even in the rare case that a single sheet begins to lift, the rest of the roof should stay intact. The main weakness of asphalt shingles is that they are connected in three-tabbed sections, each overlapping with the next. This construction allows the wind to lift individual shingles, exposing more surface area and causing larger sections to lift away from the roof decking. Single singles can crease and tear, destroying their waterproofing qualities.
Even if shingles are not torn or bent away from the roof’s surface, the granules on asphalt-shingled roofs can become compromised by the incessant friction caused by pounding rain and winds, eroding away until the shingle is no longer effective. Friction and erosion are less of an issue on metal roofs due to their relatively smooth surfaces. Heavy winds can easily pass over a metal roof without affecting it, and rain does not cause erosion as it does with an asphalt-shingled roof.
Further, homes in hurricane country can utilize higher-grade metal with thicker sheets when constructing metal roofs. These roofs are heavier and can provide additional resistance to wind to guard against bending. Overall, metal roofs are made to completely negate most of the detrimental qualities of shingles. If you are living in hurricane country, a metal roof can save your house and may even save your life.
Types of Metal Roofs
Even in hurricane-prone areas, you may see two different type of metal roofs, classified as either corrugated or standing seam. Corrugated roofing can be easily recognized as it features alternating ridges and grooves, which must be fastened to the roof deck with exterior screws. Corrugated metal roofs are the most common type of metal roof as they are less expensive while still retaining the energy efficiency benefits that make metal roofing so popular.
The other type of metal roof is growing in popularity, especially in regions affected by hurricanes. A standing seam metal roof can be recognized by the lack of visible screws on the roof. It also has visible indentations or ‘seams’ where the metal is folded together to hide the screws which hold the metal roofing on. Many homeowners appreciate standing seam metal roofing for its sleeker appearance and superior weatherproof qualities.
Corrugated Roofing Versus Standing Seam Roofing in Hurricane Country
Corrugated roofs have more limitations than standing seam roofs. It will be difficult to find a corrugated metal roof lower than 24 gauge, and since a lower gauge means the metal is thicker, a corrugated roof may not be as heavy as a standing seam roof. Weather tightness may also fall short when it comes to a corrugated roof as the screws must protrude through the decking to stabilize the metal. In hurricane-prone areas with heavy winds and rain, this could mean a higher chance of leaks. In addition, with weather and debris constantly affecting the unprotected screws, corrugated fasteners are more prone to damage and will need to be replaced periodically.
By contrast, because of their structure, standing seam roofs can use lower gauge metal sheets that are heavy enough to resist lifting and bending. The lack of visible screws means standing seam fasteners are not exposed to the elements and are less likely to introduce moisture into the roof decking. A standing seam roof can withstand many of the harsh weather elements that could affect a corrugated roof over an extended period and may require less maintenance after a powerful storm or extended hurricane season.
Corrugated or Standing Seam Roofs and Wind Ratings
Many of the differences noted above affect the most crucial element of a roof in hurricane country—its wind rating. Depending on the specific roofing product involved, you will see a wind rating difference for corrugated and standing seam metal roofs. In general, standing seam roofs with interlocking or overlapping panels and concealed fasteners earned better wind ratings than corrugated roofs with exposed fasteners. They provide less opportunity for high winds to get underneath and begin lifting roofing panels.
As mentioned earlier, standing seam roofs also allow for thicker, lower gauge metal to be used in the construction of the roof. Another bonus to standing seam roofs is that they can be used on homes with reduced slope roofs. While corrugated metal roofs have a minimum slope ratio of 3 inches to 12 inches, standing seam roofs can have a pitch as low as 1 inch for every 12 inches. A lower pitched roof can allow wind to pass unhindered, resulting in less overall damage.
Should You Install a Metal Roof on Your Hurricane Country Home?
With the benefit of a thicker gauge, lower pitch, and protected screws, standing seam roofs offer by far the greatest protection out of the two metal roofing options available. A metal roof will also provide more protection, energy efficiency, and eco-friendly benefits compared to asphalt-shingled, or wood shake roofs. To learn more about the financial, home value, aesthetic, and customizable benefits of a metal roofing system on your home in hurricane country, find a qualified metal roofing contractor to discuss your options today.