Temperatures are climbing along with energy bills. Businesses and homeowners are seeking cost-effective ways to beat the heat. In addition, California has mandated that all new residential roofs in climate zones 4 and 8-15 must use certified "cool" products, spurning the white-roof trend. However, cool roof shingles come in many colors. But are they worth it just to avoid the glare?
Cool roof shingles are worth it if building or replacing a roof in a sunny area, especially if it is high-sloped. Cool roof shingles are initially more expensive, but they last longer, save on energy bills, are low maintenance, and provide a greater range of color options.
Cool roof shingles are not the only option to reduce a business or home's temperature and energy costs. For instance, low and flat roofs can be upgraded with a cool coating that looks similar to white paint. Applying a single-ply membrane is even better, as they are sturdier and provide better protection. However, steeper roofs often require different solutions.
When are Cool Roof Shingles Worth it?
First off, cool roof shingles are worth it for businesses and homeowners, especially if you:
To know if cool roof shingles are right for your business or home, it's essential to understand what they are and when they can be used.
What are Cool Roof Shingles?
Cool roof shingles are a type of reflecting roofing, meaning they don't absorb light that can create extra heat in a home and building. They are growing increasingly popular as temperatures break new records and energy costs soar. Quality cool roofing shingles are made up of solar-reflecting granules and are generally slightly thicker.
It is the presence of the granules that allows cool roof shingles to be available in other colors besides white. The broader range of colors makes it easier for homes in strict HOAs to have a cool roof and remain compliant.
What Style Roofs can Use Cool Shingles?
Cool shingles can be used for sloped roofs. Shingles generally require a minimum 2:12 pitch, meaning the roof rises two inches vertically in a foot. Thus, cool shingles are an excellent option for roofs with a 4:14 pitch or greater (18.5 degrees or more). Those with flatter roofs should consider other options, such as applying a coating or membrane or installing a green roof (covering in plants or other vegetation).
Conversely, these other options become increasingly more challenging the steeper the roof. For instance, the coating risks being uneven on a roof pitch of 4:12 or higher. In addition, green roofs weigh more, so some buildings and homes are not structurally designed to support them.
Do Cool Shingles Save Energy Costs?
Cool roof shingles do save energy costs during the summer. Studies have shown the exact figures depend on the type of cool roof used and the region the building or home is in. However, the Cool Roof Rating Council estimates home and building owners save 7% to 15% in cooling costs. In addition, having a cool roof may make you or your business eligible for a tax credit or deduction.
Do Cool Shingles Increase Heating Costs?
Cool roof shingles make the house slightly cooler in winter, which may increase heating costs. However, research has shown that the extra heating required is marginal, and businesses and homeowners still save overall in areas with warm to hot summers.
Should I Replace my Roof with Cool Shingles?
Cool roof shingles are an excellent choice if you are putting up a new build or the roof or your home or business needs to be replaced. While cool roof shingles cost slightly more than regular shingles, most of the roofing cost is labor.
Thus, the more expensive shingle doesn't have a significant impact on the overall roofing costs. In addition, they will save you money in energy costs, and they last longer.
However, if your current roof is in good shape, your savings in energy costs and tax benefits will not compensate for the early reroofing expense. You can reduce energy costs by exploring other avenues, such as adding insulation or installing solar panels. That latter creates shade on your roof, reflects light away, and produces energy.
Why do Cool Roof Shingles last longer?
Cool roofs last longer because they stay cooler and their materials absorb less heat. Heat absorption breaks down materials, reducing their life expectancy. Extreme temperature fluctuations are also hard on roofs, increasing the chances of cracking and splitting. Thus, quality cool roof shingles will require less maintenance and last longer, reducing the number of times a roof needs to be replaced.
What to Consider in Cool Roof Shingles
Cool roof shingles come in a variety of quality and ratings. The standard of shingle impacts how well it will cool a home or building, if it meets the requirements for a tax credit or deduction, and, in California, if it meets the area's Energy Codes. The three main areas to consider in a cool roof shingle are:
Solar Reflectance
Solar reflectance applies to visible and invisible light rays bounced back into the atmosphere, away from your building or home. Roof shingles are typically measured based on their initial abilities and three-year performance. Ideally, a cool roof shingle should have a minimum initial rating of .25 and a three-year rating of at least .15.
Thermal Emittance
Thermal emittance in roof tiles refers to how much heat is transmitted to the building or home. The rating ranges from 0.0 to 1.0, and the higher it is, the less heat is emitted.
Solar Reflectance Index (SRI)
The Solar Reflectance Index (SRI) ranges from 0 to 100 and indicates how hot a shingle becomes when exposed to direct sunlight. The higher the number, the cooler the shingle. Conversely, the lower the number, the more suited a shingle is for playing the game, “Is it hot enough to fry an egg?”
Lighter-colored cool roof shingles will generally have a better rating, but thanks to the solar-reflecting granules, the difference is typically not substantial.
Final Thoughts
Cool roof shingles are worth it for steep roofs to new builds or homes and buildings needing reroofing, especially in hotter climates. These shingles offer options outside of white while lowering temperatures and energy costs. However, quality does vary, so choosing those with better ratings is essential. (Related: Energy Efficient Roofing: What Homeowners Need to Know Before Making a Deposit)