For homeowners looking to reduce the cooling costs of their home, make it more eco-friendly, or simply just have it take on a more natural aesthetic, a cool roof may be the right decision.
If you’re wondering what a cool roof is, what it costs, and if it’s worth it, you’ve come to the right place. This article will examine the differences between a traditional roof and a cool roof. We will also cover what to expect financially and the pros and cons of choosing a cool roof.
What Is a Cool Roof?
A cool roof is a specially designed roof made of highly reflective paint, sheets, shingles, or tiles. This reflection allows sunshine to bounce off the building’s top, so the roof and the home absorb significantly less heat.
There are several variations of cool roofs. However, their primary purpose remains the same—reducing cooling costs for homes located in warm to hot climates.
The cost of investing in a cool roof can potentially be very quickly worth the price of admission, as the money spent upfront could pay for itself in terms of savings on cooling costs.
How Much Does a Cool Roof Cost?
Cool roofs are usually comparable to conventional roofs in cost—sometimes, they are even cheaper.
Cool roof coatings typically cost 75¢-$1.50/sq foot. Single-ply cool roof membranes range from $1.50-$3/sq foot.
Covering an average-sized home in cool roofing generally costs between $1,695 and $6,783.
The savings are more apparent when installing a new roof on a new build or replacing the roof of an existing home.
The hotter your area, the more likely a cool roof is to be financially feasible.
According to S. Konopacki’s publication, cool roofs in California save almost .50¢/square foot. That figure factors in the following:
- Cool roofing installation
- Cool roofing products
- The increased wintertime heating costs
Conventional Roof Rates
As mentioned, many times you can expect to pay more for a conventional roof than a cool roof application.
In comparison to cool roofing, the material costs to cover an average-sized home with a conventional roof generally range from $5,652 to $113,050.
Regular roofing prices range as the following, according to Fixr.com:
- $2.50 to $15/sq foot of metal
- $3 to $12/sq foot of asphalt
- $5 to $16/sq foot of tile
- $10 to $16/sq foot of slate
- $21 to $25/sq foot of solar
- $21 to $50/sq foot of bitumen
Paying for a Cool Roof
There are several programs available to assist homeowners in making energy-saving home improvements.
One notable program is the Property Assessed Clean Energy (PACE) financing program. This program allows owners to begin their clean energy projects without upfront costs, making clean energy improvements more accessible.
PACE allows homeowners to repay the bill as part of their property taxes, enabling homeowners to begin to reap the benefits of their new cool roof as they slowly pay off their clean energy home improvement.
Click here to find out if you prequalify for PACE.
A More In-Depth Look at Cool Roofs
Not all cool roofing applications are the same—there are a few different methods to choose from, depending on your needs and your home’s specifications.
Cool roofs come in three primary varieties: retrofit, re-cover, and replace.
Retrofit
Retrofit cool roofing is a heat-reflecting material that is installed over the existing roof.
Usually, this material is a special kind of light-colored paint that you can roll over your existing roof in a day or two. Retrofitting is the most affordable version of cool roofing.
It does less to protect the preexisting roof from new water damage than the other types (though it may cover some minor leaks), but it gives the home the reflective and cooling benefits of a cool roof.
In addition to cooling the roof, it also protects the existing roof from further UV damage.
This coating also makes the roof look newer, thanks to the new color it adds.
Re-Cover
Re-covered cool roofing is a waterproof surface. This version is more costly than retrofitting but cheaper than replacement.
A single-sheet membrane, usually tile, is installed over the existing roof. The tile is glazed for an added layer of protection in tropical climates. This type of cool roof is only available for gently sloped roofs.
For steep-sloped roofs, metal is a viable option. They are available in oven-baked, natural metallic, and granular-coated surfaces.
Cool roof re-cover membranes will protect your home from further water damage and also reflect heat to keep the house cool in the summer.
Replace
Replacement cool roofing is a completely new roof that requires an all-new structure, insulation, sheeting, and an exterior protectant.
This is the most expensive version, but it also has the most significantly beneficial and long-lasting properties.
Reflective shingles are the best option for a new or replacement roof. Light-colored shingles are the preferred version; however, new technology still allows the granule components of darker-colored shingles to repel solar heat.
For urban (or otherwise flat or shallow-pit roof) buildings, green roofs are an option.
Green roofs provide an added layer of insulation and can be used to plant a rooftop garden or be covered in native grasses, shrubs, or even trees.
This roofing style is the most expensive but can create a more natural living space for residents, while significantly reducing the urban heat island effect.
The Common Cool Roof Coatings
Luckily, even if you’ve already installed a darker roof, you can convert it into a cool roof by applying one of the cool roof reflective coatings discussed below:
- Aluminum coating: It combines resin and aluminum flakes to cover hot asphalt. This combination reflects between 50 and 70% of solar heat.
- Roof membrane: You can add a roofing membrane like thermoplastic polyolefin (TPO), Ethylene Propylene Diene Monomer (EPDM), or polyvinyl chloride (PVC) to your roof to reflect solar heat.
- Polyurethane foam spray: Spray foam is also ideal for roof protection. However, you must apply an additional protective coating for protection against moisture and sun damage.
- White roof coating: Applying a white roof coating helps reflect as much as 80% of the sun’s radiation. This is an excellent way to keep your roof cool in summer.
- Reflective granulated cap sheet: Cap sheets with added mineral granules make an excellent cool roofing material. These granules, together with the tar-coated fiberglass matting or asphalt in cap sheetings, reflect considerable solar radiation.
- Pigmented coating: This is ideal if you want the benefits of a cool roof coating without applying a white roof coating. Besides offering solar reflectance, pigmented coating comes in different colors, including red, blue, and green. However, this option is not effective in heat reflection—it can only reflect about 20% of solar radiation.
Why Choose a Cool Roof Over a Traditional Roof?
According to the US Department of Energy, conventional roofs can exceed temperatures of 150°F.
In contrast, a cool roof in the same neighborhood with similar conditions may only reach 100°F—that’s a nearly 35 percent decrease in temperature!
Cool Your Home and Save You Money on Cooling Costs
These roofs can make a significant dent in air conditioning costs. They are also beneficial to unconditioned spaces in the home, especially porches, covered patios, sunrooms, and attached garages.
Attics are also significantly cooler, meaning that maintenance of this area is much safer during the summer months.
If your home has ducting in the attic, especially if that ducting is prone to leaks, cool roofing is an innovative solution to reduce waste and energy costs.
Of course, a cooler attic means a more comfortable home in the summer. All of these spaces mentioned can become much more bearable with an intelligently designed cool roof.
Reduction of Your Ecological Footprint
In addition to cutting your electric costs, you’re also reducing power strain on your local power grid.
For example, there is less likelihood the electrical grid will go down from overuse if you don’t need to run an air conditioner all day long to combat natural heat.
The Cool Roof Rating Council estimates that a cool roof saves homeowners anywhere from seven to fifteen percent of their total cooling costs.
So if you live in a warm climate, a cool roof can be an attractive option for these reasons alone!
An inadvertent perk of using less electricity is that smaller amounts of dangerous gases and emissions are released into the environment.
These reduced emissions include:
- Carbon dioxide
- Sulfur dioxide
- Nitrous oxide
- Mercury
Roofs that regularly reach high temperatures will age and deteriorate more quickly than roofs in shaded, cooler locations. As a result, cool roofs have a longer life with fewer maintenance visits needed than conventional roofs.
Additionally, cool roofs result in a cooler neighborhood, especially if your home is in a densely populated town or city.
This phenomenon called the “Heat Island Effect” describes how, due to heavy development, cities can be more than twenty degrees warmer than surrounding rural areas.
Asphalt, concrete, hot roofs, and brick buildings hold in heat. On the other hand, the assortment of cars, motors, and vents creates heat. So taking hot rooftops out of the equation can slightly decrease the city’s overall summertime temperature.
Why Choose a Traditional Roof Over a Cool Roof?
Traditional roofs are best suited for families that live in cold regions; cool roofs don’t hold onto heat very well; they are poor insulators.
In addition to a lack of heat retention, cool roofs accumulate significant levels of condensation. Luckily, you can prevent condensation through proper roof design techniques.
Clients who live in warm and wet places are advised to opt for conventional roofs. Cool roofs tend to grow mold, algae, grasses, and wild plant species.
In addition, live plant growth on a rooftop is detrimental to the overall lifespan and integrity of the home and its roof.
You may want to skip a new cool roof if your home already has a suitable rooftop with significant insulation.
According to an interview with Tuscon roofer Daniel Roberts, installing a cool roof over a house with ten to twelve inches of insulation will result in “negligible” energy savings.
The Final Word
Deciding to cover, re-cover, or replace your home with an Energy Star roof is a big decision.
Whether this type of roof is right for your family depends on your goals, location, climate, budget, and roof type.
While a cool roof will helpfully reduce the amount of solar heat your home absorbs during the summer, it also reduces solar heat received during the winter, which can be an issue for some.
Did you know roof overhangs can save you both money and energy? It’s also a viable option for roof upgrades if you don’t have them installed yet.
You can also discover why SIP roof panels are also great for increasing your home’s energy efficiency rating!