Cool Roofs for Hot Climates

Wood shake roofs by Tropical Roofing & Raingutters Inc. offer a natural look and a lot of character, with its color, width and cut variations. Location courtesy of Homeworks Construction Inc. Photo by Aimee Harris.

While principally a commercial supplier for big projects, such as the Blaisdell Arena, All Weather Surfaces also has a steady supply of residential roof products for Hawaii homes.

“We are finding increased interest from residential homeowners in roofing products that have dual benefits: protection and cooling—using our elastomeric coating systems,” says AWS president Rick LeGrand.

“We carry two premium acrylic-membrane systems: our White Lava Roof Coating, a rubber, waterproof product that radiates heat away from the roof. The other is our Tropical Roofshield Coating—the ultimate roof coating system, with ceramic-titanium pigments to reflect and dissipate heat away from the home,” says LeGrand.

Green Is Cool

Mark Silva, vice president of Macsteel Hawaii, tells us that the coolest innovations in the metal roofing industry are focused on the green building initiative.

“This initiative promotes the use of building materials that are environmentally friendly, recyclable and cost efficient. Green buildings, both residential and commercial, actually last longer, reduce operating costs (less electricity required to cool), and enhance resale values,” says Silva. New heat reflective paint coatings on metal roofs incorporate color pigments that reflect more heat than comparable non-reflective paints. Each percent of increased reflectance reduces roof temperatures by one degree, resulting in cooler buildings and less energy use.

This green-tinted metal roof is only one of the many color options Macsteel Service Centers USA has to offer. The company has manufactured high-performance, premium metal roofs in Hawaii since 1975.

Custom Metal Roofing, located on the Big Island, is also inline with the green initiative. Custom Metal Roofing has been a premier metal roofing and siding manufacturer in Hawaii since 1963. Its expanded product line includes copper, aluminum and aluminum-zinc (Z-NAL) coated steel. The aluminum and steel panels are available in 14 premium Ultra-Cool® heat reflecting colors. It is premium because it is based on a minimum of 70 percent polyvinylidene fluoride (PVDF) resin technology. PVDF is a kind of crystal polymer with good resistance to wear, high temperature, corrosion and weather, which also has good electric insulation. Also, it is anti-ultraviolet ray and anti-radiation. It is new because it dramatically increases the reflectivity to such a degree that the product meets the Energy Star® specification for Cool Roofs. Ultra-Cool reflects heat away from buildings, so interior spaces are cooler. That means considerably lower energy costs.

Architects and builders have long known the value of metal roofing. It is virtually seamless; it is light weight; the coating systems are durable and won’t fade, and the color choices are much broader than with any other material.

It’s the best of both worlds—aesthetic freedom and energy efficiency. Smart colors, smart savings.

Curvaceous Steel

Macsteel Hawaii, manufacturer of commercial and residential metal roofs, recently introduced a new MAC 150 profile and standing-seam panel-curving machine to its growing metal roofing product lineup.

Macsteel’s newest roof material, MAC 150, lends its curves to the Schofield Barracks shopping center.

The precision curving system produces a smooth, convex-curved panel for unique applications, such as roof dormers, and arched or vaulted roofs. Panels can be curved to a minimum radius, as low as 36 inches. One of the latest projects utilizing the new curved panels is the shopping center expansion at Schofield Barracks.

Cooling a Hot House

During our Island summers, attics and interior roofs can reach temperatures of up to 150°F. High temperatures cause radiant heat to expand downward, creating a hot house. The same expansion occurs within an open-beam or vaulted ceiling. This heat build-up results in greater wear and tear on the roof structure and a huge increase in energy costs to cool the house.

A simple and extremely effective solution to purging the house of heat is a venting fan.

Skylights of Hawaii recommends its Cyclone solar powered venting fan, a relatively silent yet powerful 12-inch, five-blade, 20-watt unit that runs off photovoltaic panels. PV is a solar-power technology that uses solar photovoltaic arrays, or solar cells, to provide electricity. The Cyclone moves 1,275 cubic feet of air per minute from the inside of the roof, attic space or house interior with an open-beam, cathedral ceiling. The system installs easily in any roof, with no major electrical hookup necessary, no assembly and no risk of fire.

“It can drop the temperature by as much as 40 degrees in your attic or roof space and lower the interior temperature of the house by 10 to 15 degrees,” says sales manager Jeffrey Tong. “Reducing the inside roof temperature not only saves on air conditioning bills, but actually extends the life of the roof itself,” he adds.

Cool Roofs Al Fresco

AeroSail, Skylights of Hawaii’s innovative, functional and aesthetically pleasing line of outdoor shade structures, ranges in size from 135 square feet up to 22,000 square feet—from large umbrella size to “warehouse” coverage.

Designed for both residential and commercial usage, AeroSail translucent structures can be erected at very competitive prices. They are made from a breathable, tensile, waterproof fabric and are immensely strong—engineered to resist winds of 180 mph. They provide protection from harmful UV radiation while reducing shaded-area temperatures by 20°F or more.

“Our AeroSail product is synergistic with the Hawaii climate, designed to replace more traditional structures of wood and concrete—but lighter, airier and more pleasing to the eye,” says Tong.

Roof tiles and shakes are available in a wide range of earth tones, from Gerard Roofing Technologies.

Roofers on the Rise

Roofing contractors throughout the state are having a busy year keeping up with the residential and commercial building boom in the Islands. Bruce Place, of Gerard Roofing Technologies, reports a lot of activity on the Big Island.

“The Big Island market has been particularly active so far this year, with people building new homes and looking for durable roofing products. Since our appearance at the Home Show Remodeling Expo in Kona, we’ve had a surge of interest in our Gerard product—very durable, stone-coated steel tiles and shakes that are lighter than just about any other type of roofing available, other than maybe aluminum. The colors are fade resistant, since ultraviolet rays don’t affect the ceramic coating,” he says.

For accuracy when selecting a color, Place recommends choosing from a sample of the actual roofing material, since a brochure often doesn’t do the actual product color justice.

Plan Ahead for Re-Roofing

How can homeowners keep the lid on stress and costs?

There is much that the homeowner can do to avoid hassles and wasted effort and minimize expenses before making a commitment to a roofing contractor.

“The homeowner needs to exercise due diligence by thoroughly researching contractors,” says Clinton Murakami, owner of Murakami Roofing. He recommends that homeowners ensure a contractor’s license is active by checking with the Department of Commerce and Consumer Affairs (DCCA) Licensing Division.

Making sure a contractor’s insurance is up to date and checking with the Better Business Bureau are also wise moves.

Once you have chosen three reputable contractors, you need to determine when you want the work done. Begin by getting bids in April, after tax time, and plan on having the work completed during the summer months. Since re-roofing can be a messy undertaking, you should schedule any other house-related work after the roofing—especially guttering and painting.

Who should check for termites?

Asphalt shingles, from Murakami Roofing, are cost-effective and durable.

It’s also smart to have a termite inspector check for any damage in the roof before proceeding.

“If I believe the roof supports are structurally sound, I can begin roofing. But if there’s any sign of termite damage—especially evidence of live termite damage, I’ll alert the homeowners and advise them to have the problem dealt with before proceeding with the roofing,” says Murakami.

How long does the job take? Depending on the condition of the old roof, a three-bedroom home between 1,800 square feet and 3,000 square feet usually takes two to five days.

“An old, flat, tar-and-gravel roof, especially one where an overabundance of tar has been used, can take longer to get off,” says Murakami.

Which materials should homeowners use?

Reputable roofers can advise the customer on the most suitable roofing material according to the existing roof structure, location and the homeowner’s budget.

“The bulk of residential homes have asphalt shingle. It’s tried and true, by far the most economical, and its longevity has been improved considerably,” says Murakami. “My second choice would be aluminum shake for cost, lightweight and durability,” he added. Particularly with a flat, low-sloped one, simply putting a new layer of material over the existing roof can also result in considerable savings.

“This can save the homeowner up to $4,000,” says Murakami.