A cool roof has two important properties: it reflects sunlight (reflectivity) and it releases heat (emissivity). Both of these features lead to lower electricity usage and greener lifestyles. Some of the following 5 suggestions require a brand new roof, while others can be applied to your existing roof.
1. Reflective Coatings
A shingle roof is cheap and easy to install, which is why it represents 80% of the roofing marketplace. The only problem is that asphalt shingles and other varieties aren't the greenest choices because they absorb heat and transfer it into the home.
If you love the look (and price) of shingle roofs, however, you aren't stuck with a high carbon footprint. Consider covering your roof with a reflective coating, which is a thick substance applied to the shingles like paint.
These substances are usually white or pale gray in color, which automatically improves the reflective properties of your shingles. Less heat is absorbed by the roof, so your house stays cooler even in the middle of summer.
2. Cool Roof Coatings
Metal is an excellent cool roof material by itself because it is highly reflective and because it lasts longer than most other roofing materials. It bounces sunlight away from the home so that less warmth is transferred indoors.
However, metal has low emissivity, which means that it doesn't release heat easily once it is absorbed. One way to counteract this property is to cover the metal with a cool roof coating, which decreases the amount of heat absorbed through the roof.
Like the reflective coating mentioned above, a cool roof coating is painted onto the roofing material. You might need to reapply coatings every few years to retain the benefits, but it's much cheaper than installing a brand new roof.
If you don't want to invest in coatings for your roof, a can of paint might provide enough light reflection to reduce your cooling bills and decrease your carbon footprint. This is the perfect solution if you know your roof will need to be replaced in a couple years.
You probably remember from high school science class that light colors reflect light, while dark colors absorb it. Select a light-colored paint to increase reflection of sunlight from the top of your roof.
4. Built-Up Roofing
Another option is to use a build-up material, such as bright white gravel, to reflect sun and reduce heat absorption. This cool roof strategy uses multiple layers of different materials to create several plys, or piles, of insulation and protection. Common materials include:
Built-up roofing, or BUR, is appropriate for flat and low-pitched roofs, whether on commercial or residential buildings. Using the white gravel mentioned above create a top layer of reflective material, but the building still benefits from the insulation of the lower layers.
5. Cool-Colored Tiles
If your home is ready for a new roof, consider slate or clay tiles to improve energy efficiency. Tiles with pigments in cool colors, like white and pale blue, reflect more heat and reduce heat absorption.
In fact, cool roof tiles can reduce the cost of air-conditioning your home by as much as 30%. The type of tile and its color pigments both play a part in creating a green home. It's also extremely versatile and looks great when paired with many different home styles, including:
Tile is more expensive than other roofing materials, but it's also durable and long-lasting.
Cool roofing materials and strategies do more than just lower your energy bills; they also make your home more comfortable in the summer. Consult with an experienced roofing contractor like one from dsbahr.com to discuss the best cool roof options for your home.