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Putting a Lid on Paradise: Metal Roofing is a Good Option in Coastal Regions

The United States is a big and beautiful country with nearly 100,000 miles of spectacular shoreline from sea to shining sea.

Life in coastal regions can be idyllic, though it is not always (with apologies to Jimmy Buffett!) just “strummin’ a six string on the on the front porch swing and smelling those shrimp beginnin’ to boil.”

Owning a home in coastal areas, especially in the Hurricane-prone Gulf of Mexico from Texas to Florida, and along the Atlantic seaboard, brings its own unique hurdles as the elements can pose a risk to man and material.

“Building in coastal regions presents a different set of challenges than some other areas of the country,” wrote Metal Architecture editor Marcy Marro. “Having to deal with salt spray and hurricane-force winds and rain make metal roofing a good option for homeowners.”

Marro argues that metal roofing not only can bring design and style to your home, but can also tackle the tough weather in coastal areas because of three main factors:

  • Strength
  • Longevity
  • Low Maintenance

Coastal Considerations: More than the 1,500-Foot Rule

One of the unwritten rules of installing a metal roof in a coastal area is to make sure you have special finishes or paint if your home is within 1,500 feet of salt water or the coastline.

The 1,500-foot rule, however, is just one of many considerations when building with a metal roof in coastal areas.

Environment factors that will influence your choice of metal roofing material along the coast include:

  • Average rainfall
  • Amount of fog
  • Prevailing winds
  • Breaking surf nearby vs. calm waters
  • Climate zone
  • Humidity

“An area with high rainfall will gets lots of natural rinsing and a better scenario than low rainfall, likewise, areas such as Puget Sound with no breaking surf (low salt spray) and high rainfall are considered a milder marine environment than say the southern coast of California with strong surf (high salt spray) and low rainfall. All of these factors influence the frequency and type of cleaning and maintenance that may be required to ensure good long-term performance,” Michelle Vondran, technical manager at NS BlueScope Coated Products-North America, told Metal Architecture.

Maintenance requirements, along with your metal roofing materials resistance to salt (chlorine) and dynamic appearance also factor into a design decision.

Providing Shelter from the Storm: Metal Roofing

Many builders have discovered in recent years that insulated metal panel (IMP) roofing can meet the strong building codes required in hurricane zones such as Dade County in Florida.

“A metal roof can withstand decades of abuse from extreme weather like high winds, heavy snow, hailstorms and even wildfires. Metal roofing has a 140-mph wind rating, meaning it can withstand wind gusts up to 140 miles per hour,” says the Metal Roofing Alliance.

Metal roofing systems, such as those manufactured by Green Span Profiles, have wind resistance and uplift resistance that meets and even exceeds new building code requirements.

Green Span Profiles insulated metal panel wall and roof system, for example is approved for installation in the HVHZ after undergoing a series of tests including:

  • 2000-hour Accelerated Weathering Test
  • 2000-hour and 1000-hour Salt Spray Test
  • Large Missile Impact Test
  • Uniform Static Air Pressure Test
  • Susceptibility to Leakage Test

Roof Slopes and Shapes that Work in Coastal Areas

Careful consideration of your roof slope can be an important factor when designing and choosing metal roofing systems in coastal areas.

While standard roof shapes and slope will work in coastal regions, the safest avenue is to have a professional engine determine the best panel profile that works for your project based on:

  • Substrate
  • Eave height
  • Wind speed in area
  • Roof type
  • Roof slope

Thickness of IMPs chosen along with proper spacing will influence the framing and substrate of the metal roof.

“If the specific region is low in rainfall, a higher slope is better,” Vondran, who recommends a slope of at least ¼:12 to allow for good drainage, told Metal Architecture. “The overall design should allow for good water shedding as well as ease of required maintenance. Sheltered areas such as under eaves, will need to be accessible for freshwater cleaning.”

A Word About Warranties and Maintenance

The 1,500-foot rule should always be respected, as your metal roof may not be covered under its warranty if the home is close to the shoreline and a special coating or paint is not used.

Always make sure that you read the fine print and determine if your metal roofing paint and/or coating is suitable for coastal areas.

Some experts say to be on the safe side, consider not only the 1,500-foot rule but if your project is within one mile of salt water, consult your IMP manufacturer to determine its performance for the region.

Mark Robbins, senior editor at Metal Construction News, says that choosing the right coating system can help minimize corrosion.

“Wind-blown salt spray can be destructive to metal roofing and wall assemblies. Metal is well known for its longevity, but some metals will corrode in coastal environments. Although not all metal roofs and walls corrode at the same rate, over time, salty sea air and humidity will react on them and they will deteriorate,” writes Robbins.

Also, low maintenance of metal roofing does not imply “maintenance free” and homeowners will want to closely follow maintenance requirements for the metal roofing materials and finishes they choose.

Maintenance could be the key to how long you can enjoy your metal roof with Waypoint Property Inspection of Florida saying that “you metal roof could last 40-50 years, sometimes longer, However, it depends on location and maintenance. ” A metal roof on the beach with no maintenance could last only 15 years. On the other hand, an inland metal roof with maintenance could last 60 years or longer.”

Contact Green Span Profiles today to find out more about their insulated metal panel roofing system that will provide a long-lasting lid to your piece of paradise.

Topics: Insulated Metal Panels, Safety, Metal Roofing, Construction