New roofs are made with technology and materials that reflect more sunlight away from your home to help keep you cool during the hot summer months. A new roof will have a higher “reflectance value” than older models, meaning they don't absorb as much solar heat. A cold roof is designed to reflect more sunlight than a conventional roof, absorbing less solar energy. This lowers the temperature of the building, just as wearing light-colored clothing keeps you cool on a sunny day.
Conventional roofs can reach temperatures of 150°F or higher on a sunny summer afternoon, with sunshine. Under the same conditions, a reflective ceiling may stay more than 28°C (50°F) cooler. This can save energy and money in buildings with air conditioning, or improve comfort and safety in buildings without air conditioning, by reducing heat flow from the roof to the occupied space. Most cold roofs have high “thermal emissivity”, the ability to emit heat by emitting “thermal infrared radiation”.
Almost any type of building can benefit from a cold roof, but consider climate and other factors before you decide to install one. Talk to your roofer to ensure that all products planned for your new roof have the highest Energy Star rating. In fact, according to Energy Star, Energy Star shingles can reduce the surface temperature of a roof by up to 50 degrees, reducing the amount of heat transferred to a house or building. This decrease in roof temperature translates into a 10 to 15 percent reduction in the amount of air conditioning or heating needed to maintain a home.
In most cases, a cold roof will stay at least 50° F cooler than a non-cold roof of the same color and construction, allowing you to get the roofing style you want, but with a better energy efficiency rate. Contact a trusted local roofing company, such as Advanced Roofing, to start your next roofing project. The worst roofing materials in terms of energy efficiency are aluminum roofs and unpainted metal roofs. In fact, a federal study has shown that plywood under dark roofs under direct sunlight is consistently 10 to 15°F warmer than plywood boards under light-colored ceilings.
If the roof is not well ventilated, hot air can be trapped inside the attic and cause the entire house to gradually heat up, like an oven. Any accredited roofing contractor will tell you that proper roof ventilation is the best way to ensure your home stays cool in summer. The amount of energy you'll save depends on several factors, such as the climate and environment of your home, the degree of insulation of the entire roof, the type of roof you have, and the efficiency of your heating and cooling system. In cold climates, roofs can accumulate moisture through condensation, and cold roofs may be more susceptible to accumulating moisture than dark roofs of the same design.
A cold roof doesn't necessarily cost more than a non-cold one, especially if you're installing a new roof or replacing an existing one. Keep in mind that concrete roofs and clay tile roofs have a higher starting price than cheaper alternatives, such as asphalt, but that they will pay for themselves in the long term in terms of energy savings. Polyurethane foam spray ceilings are constructed by mixing two liquid chemicals that react and expand to form a solid piece that adheres to the ceiling. If you are building a new home, you can decide during the planning phase what type of roof to install and if it should be a cold roof.
Metal roofs with vertical seams are formed by joining metal panels with raised vertical joints; joined panels cover the roof. So what is the most important factor in how the roof affects the temperature in your home? The combination of roof construction and attic ventilation. Before hiring a roofing contractor, you can call ahead to make sure they have the energy-saving shingles and roofing materials you're looking for. Their rugged construction also helps them withstand strong winds, improves their fire resistance (useful if lightning strikes the house) and makes them less susceptible to hail damage, reducing roof maintenance and repair costs.