I have had many of my home design clients ask - "What's the best roofing material I can use in coastal areas subject to hurricanes?"
I have asked this question myself many times.
The answer: "It depends"
Metal roofing, such as standing-seam steel roofing can perform very well in hurricane-force winds. If you consider wind-resistance to be a good factor (it is), the standing-seam steel roofing performs much better than other roofing materials. For one thing, standing-seam metal can be made in large sheets which are more of a structural component adding to the strength of the
roof system. Steel sheeting can be calculated and engineered to perform a better function in holding the roof on in high winds. Depending on the thickness and size of steel sheeting it can have more resistance to blow-off than many other roofing materials. Another plus for metal roofing is their superior ability to dispel lighting strikes. Metal roofing has been very popular in coastal areas lately, more due to fashion than finance. Metal roofing is not a good material to store extra material for future repairs, its large and bulky and the replacement roofing would still not match the old roof, because of sun exposure. One drawback is that metal roofing is more expensive that other roofing types. The Kynar® coated colored metal roofs are a bit more expensive than "5-V" or corrugated galvanized Metal roofing but will last longer than some other roofing types and are more energy efficient than other roofing materials. If you want to save energy, lighter colors and silver galvanized finish will be cooler and save more on your cooling bills.
Copper roofing oxidizes over time to a dark brown patina and could become a heat sink. If we all switched our roof color from a dark color to a light color, we would slow down the greenhouse affect on the entire planet! Copper and Stainless Steel are other choices but are very, very expensive, however they both last a very, very long time. A good economical selection for a metal roof is the Galvalume coated galvanized finished "5-V" roofing or corrugated roofing. Galvalume roofing will not rust as quickly as standard galvanized roofing. Some metal roofing has been tested at wind speeds up to 200 MPH.
Green Tip! Another great thing about metal roofing is its ease of recycling. Other than wood shakes, metal roofs are very "green."
However, this is not to say other roofing types don't have merit, or are inferior.
Composition or "Fiberglass-Asphalt" shingles have been made by several companies to be both wind-resistant and durable. Fiberglass-Asphalt shingles are a lot more economical than metal roofing and are easier to replace after a storm. Several roofing contractors suggest roofs that are less than 6/12 pitch will be services before steeper roofs because they are easier and faster to walk on. Steep roofs and roofs that are more than one story off the ground require extra safety precautions (OSHA laws) for roofers. Therefore, after a hurricane, you will see the lower pitched roofs and lower houses repaired first. Fiberglass-Asphalt shingles can be made to be fire-resistant, with Class-A being the best. Several companies make Wind-Resistant shingles to 130 MPH that meet the UL highest standard for impact resistance - UL 2218, Class 4.
Many different colors and textures of roofing are offered in fiberglass-
asphalt shingles and they seem to have more variety than other roofing choices. Fiberglass-asphalt shingles have a life-span of 15-30 years and are subject to mildew and moss. The asphalt in this roofing makes it less "Green" than other roofing types, it's environmentally unfriendly. Extra replacement shingles can easily be stored away for later repairs.
Wood
shake or shingles are another possibility. Wood shakes and shingles come in several lengths and thicknesses. Shakes can be hand-split (more expensive) or resawn, which are called shingles. Wood shakes are certified and graded by the Cedar Shake & Shingle Bureau. For instance, No. 1 grade Blue Label® western red cedar shake roofing is one of highest quality wood roofs. Wood is a natural fuel for fire, so it needs a fire-retardant treatment to make it good for roofing use. I would not recommend wood shake roofing unless it was fire-retardant treated. Wood shakes are more "Green" than some other roofing materials. However, wood can split, rot, grow mold and mildew. Pressure treated wood is also available. Wood shakes perform a little better than fiberglass-asphalt roofing but replacement will never match the original shingles. Wind tests done in Dade County, FL found Certigrade® shingles withstood wind speeds of 173 MPH, whereas Certigrade® shakes withstood wind speeds of 245 MPH.
Wood weathering will create an oxidized grey tone to its surface and it is impossible to match with new wood.
Over time however, the shingles will get back to their oxidized-grey finish. Shingles used on some old Coast Guard stations are still in place over 200 years, and they still look great.
See my next post for more information about roofing on Monday, September 29, 2008.
Dennis Mercer
Before you select a cottage design, consider the following tips in helping you with your choices. Any good design should be based on a collection of decisions, ideas, wishes and a great deal many tradeoffs that have to be considered and weighed in order fit your family to your budget. Any successful design is one that keeps on giving your family the best vacation it can have... for a lifetime. 
