Top 10 Roofing Options for Hotter Climates

Key Insights

When thinking about keeping a building cool, air conditioning is often the first thing that comes to mind. However, the primary defense against heat is a building's roof. On a scorching day, an effective roof should deflect the sun’s rays instead of trapping and absorbing them.

Imagine this: If you're sitting on a black chair and step away to grab a cup of coffee, you'll find the chair warm when you return — and it'll stay that way for a while. But if the chair is made of metal, clay, molded plastic, or slate, it might feel warm briefly but will cool down quickly by the time you get back. Traditional shingle roofs behave similarly, retaining and transferring heat. Roofing materials like felt layers with asphalt and tar trap heat and even transfer it downward into the building, while other materials reflect light and heat away from the structure.

The materials and colors of roofs play a critical role in how buildings, and even entire cities, manage heating and cooling. U.S. Energy Secretary Stephen Chu once suggested that painting all roofs and roads white or light colors could lower air conditioning energy costs by 10 to 15 percent [source: Connor]. Is it really that simple?

Before you rush to grab a ladder and some patio paint, consider which roofing materials and methods — from the traditional to the cutting-edge — are most effective in hot climates.

10: Overlays and Radiant Barriers

Just as using an umbrella or wide-brimmed hat helps block the sun on a hot beach day, roofing technology is catching up. Cool-roof coatings have seen advancements recently, with even more innovations underway. Elastomeric sealants, foam sprays, ceramic paints, and even treatments using 'recycled waste cooking oil' are showing promise in cooling roofs by applying reflective overlays. Built Up Roofing (BUR) is one way to apply cool-roof coatings to traditional asphalt or tar roofs. Claims about ease of application, durability, and energy savings vary by manufacturer, so it's important to research cool-roof options and consult with local contractors and building codes to determine what's most effective in your area.

A technology alternative to overlays is the radiant barrier, a type of roof underlayment system. This involves applying a reflective material, like aluminum, or a special spray treatment in the attic or space between the roof and home's interior. These barriers prevent heat from entering the home, keeping it cooler. Costs range from 15 to 75 cents per square foot, with models that include added insulation being more expensive [source: National Association of Home Builders]. However, with potential savings of up to $200 annually (depending on location), the installation costs might be a worthwhile investment [source: Oak Ridge National Laboratory].

9: Slate Tile

Slate roofing is a time-honored European tradition, introduced to the Americas in the early 1600s [source: Sweetser]. Known for its durability and aesthetic appeal, slate comes in a variety of natural colors and requires minimal maintenance. Lighter and earth-toned slate tiles help reduce heat absorption due to their reflective qualities, and they develop a beautiful patina over time.

While slate is one of the most aesthetically pleasing roofing materials, particularly for Mediterranean and Spanish architectural styles, it comes with a hefty price tag and is quite heavy. Its beauty and effectiveness in hot climates make it highly sought after, but the difficulty in transporting it, compared to lighter and more durable materials, can make it less practical. In areas lacking natural slate deposits, it becomes a more expensive option. Though reclaimed slate is available in some places, the costs of installation and transportation remain significant.

8: Terra Cotta and Clay

In regions such as Spain, Mexico, Italy, and the American Southwest, where the sun blazes hot, terra cotta roofs are a staple. These roofs, especially in Mission-style or Spanish architecture, have stood the test of time, with many ancient structures still showcasing clay tiles that have endured centuries under the scorching sun. The light color of clay roofing helps reflect more heat, unlike darker materials that absorb it. Modern versions of these tiles are often treated to resemble more expensive slate or to improve their weather resistance and heat-reflecting properties.

Rust and sienna-hued terra cotta tiles not only cool buildings through their material properties but also through their unique shape. Terra cotta tiles are fired in kilns, making them tougher and less porous, which reduces their heat retention. These tiles are often formed into a half-barrel or 'S' shape, creating arches that interlock across the roof. The space beneath these arches promotes air circulation and water runoff, preventing heat buildup and keeping the building cooler.

Clay and terra cotta roofs are often paired with concrete and stucco structures, and this makes sense given the weight of these materials. Both require strong foundations to support their load, as well as to withstand wind and seismic forces. A challenge with terra cotta tiles is their vulnerability to breaking in cold and wet weather. While newer manufacturing methods have addressed this issue, it is always wise to assess their durability and resistance to temperature fluctuations before installation.

7: Cool Color Concrete Tile

Concrete tiles are typically more affordable than slate and clay, but they tend to be pricier than conventional shingles. Heavy and slow to heat, concrete is an excellent roofing option for hot climates due to its durability. In developing nations, poured concrete slab roofs offer a low-cost solution to protect buildings from the elements and pests. In more advanced regions, concrete also serves as a solid barrier beneath decorative roofing materials.

Concrete tiles, though still heavy, are easier to install compared to poured concrete slabs. Fireproof and durable, concrete tiles are also porous enough to absorb dyes, which can change their color. By using 'cool colors,' concrete roofing can reflect more sunlight, improving energy efficiency and helping reduce heat absorption compared to traditional dark-colored roofing materials [source: Levinson].

Made from a mixture of sand, water, and cement, concrete tiles undergo a baking process that strengthens them to withstand harsh weather conditions like rain, heat, and wind. Some concrete tile roofs in Europe have been in place for over 150 years, still functioning as effectively as when first installed [source: National Park Service].

When installing concrete tiles, it is essential to follow the local building code requirements based on environmental conditions in each region. In places like Florida, securing tiles to withstand hurricane-force winds requires additional measures and precautions. As the saying goes, "Batten down the hatches."

6: Green/Living roofs

In densely populated urban areas, especially large cities, the concentration of dark asphalt roofs, parking lots, and roadways contributes to a negative environmental phenomenon known as the "heat island effect." These dark materials absorb heat during the day and retain it throughout the night, intensifying the overall temperature in these regions.

One way to combat the urban heat island effect is by painting rooftops and roads white to reflect more sunlight, thus reducing the need for cooling energy. Another innovative solution is the concept of green or living roofs, which feature a waterproof membrane layered with soil and vegetation. These roofs naturally cool through the soil's temperature and the growth of plants, while releasing oxygen into the air. The plants also help reduce water runoff and protect the base roofing, enhancing its durability and longevity.

While the growth of green roofs may be slowed by higher costs and limited expertise, they have been cooling buildings in modern Europe for decades. Germany is the first and only country to publish a comprehensive green roofing guide [source: Miller]. However, widespread adoption of green roofing techniques on a large scale is still years away.

5: Solar/Photovoltaic Systems

Reflecting heat back into the atmosphere is one approach, but capturing and storing that heat as alternative energy is a different challenge. If you're looking to store heat without having it accumulate inside your home or office, photovoltaic systems are a viable solution. Photovoltaic (PV) roof shingles convert solar energy into electricity. These shingles come in traditional shapes and sizes, so they don't sacrifice aesthetics the way older, bulkier rooftop panels once did.

Cost and location are significant factors to consider. As photovoltaic shingles and panels become more common, prices will likely decrease, and performance will improve. However, the technology is still not widespread, and the initial cost for installation remains high. Also, the effectiveness of solar energy depends on the amount of sunlight a location receives. Cities like Phoenix or Athens, Greece, are prime for solar power, whereas places like London or Seattle may struggle due to fewer sunny days.

4: "Rubber" Membrane Roofing

Wearing a rubber raincoat or hip waders in hot weather might seem as unbearable as a black rubber sheet roasting under the sun all day. But a rubber roof for warm climates? Surprisingly, yes. Although it's not technically made of "rubber," this single-ply white membrane roofing, resembling rubber, is an advanced technology. It's crafted from weather-resistant thermoplastic or EPDM (ethylene propylene diene Monomer), a synthetic rubber. EPDM is commonly used for commercial building roofs due to its durability, and it's a thermoset material, meaning it’s pre-molded or "set". EPDM is available in rolls or sheets, making it perfect for large-area coverage.

Thermoplastic membranes are similarly weatherproof and highly durable, often featuring a reflective white coating for cooling. Unlike thermoset materials, however, thermoplastics are more flexible and can be reworked with heat, making them ideal for roofing surfaces with a steeper slope.

Both types of membrane roofing are lightweight, incredibly durable, and reflective, preventing the sun's heat from being absorbed into the building. With their nearly seamless installation, they also act as waterproof barriers, protecting the underlying surface and providing a solid foundation for green roofing systems.

3: White Barrel "S" Tile

Roof testing conducted by Florida Power & Light in the state’s hot, humid, and sunny conditions reveals that white S-shaped concrete tiles are excellent at keeping heat out of buildings. These tiles reflect approximately 74% of the sun's energy, keeping interiors cooler [source: Better Homes and Gardens].

White barrel 'S' tiles mimic the look of traditional terra cotta roofs and share similar installation methods, benefiting from the classic raised arch structure that promotes airflow. However, unlike traditional terra cotta, these S-shaped concrete tiles in bright white reflect approximately 40% more solar energy, providing enhanced cooling benefits [source: Better Homes and Gardens].

2: White Flat Tile

Another ideal roofing solution for hot climates is flat concrete tiles, often available in a range of cool colors. A lighter alternative is the bright white flat tile, crafted from ceramic, elastomeric materials, or blends of cement and fibers. These white tiles are proven to be highly heat-reflective and long-lasting, with the white cement tiles reflecting up to 77% of the sun's rays [source: Better Homes and Gardens]. Like their barrel-shaped counterparts, these flat tiles help keep heat from entering the building.

As with most roofing materials, white roofing does require some maintenance. Regular power washing helps maintain the reflective properties of the tiles and prevents them from becoming dirty or losing their energy-efficient edge compared to more traditional shingles.

1: White Metal Roofing

In terms of reflectivity, white metal roofing doesn't quite match the performance of white flat and barrel tiles, reflecting only about 66 percent of the sun's energy. However, it does have one advantage: it cools faster at night and holds heat for less time when compared to other types of roofing [source: Better Homes and Gardens].

Although metal roofing typically costs 20 to 30 percent more than traditional roofing, it provides long-term savings through energy efficiency, durability, and reduced maintenance [source: Metal Roofing Alliance]. To maximize its benefits in warm climates, proper treatments and installation are essential. Most metal roofs are made of steel and aluminum, with copper being a more expensive option. These materials should be treated to resist corrosion, and the roofs must comply with wind resistance standards. Improper installation without slope planning and glare considerations can cause discomfort to nearby residents and drivers due to the reflected light, even if the white metal roof remains cool.