Cool Roof Technology

Though the tech was researched and developed in the 1980s, cool roof systems did not gain a lot of traction among builders and developers until around 2001. This energy-saving technology continues to become more popular as the weather heats up – especially important in South Florida, as daily 90-degree-plus temperatures drive AC costs through the (traditional) roof.

What is a “cool roof”?

The US Department of Energy defines a cool roof as one that has been designed to reflect more sunlight and absorb less heat than a standard roof. 

Cool roof technology can include highly reflective paint, tiles, shingles or sheet covering. The coatings consist of white or other reflective pigments that bounce UV light and heat off your home, rather than absorbing it, like traditional methods of roofing can. A cool roof, at its most efficient, can reflect up to 65% of the solar energy, versus the average 5-15% that traditional dark roofing reflects. Cool roof coatings may also offer protection against water, aging and damage.

Why is cool roof technology important?

Traditional roofs are built with dark, non-reflective materials. Because of this, they absorb heat, causing rooftop temperatures to rise significantly above the ambient air temperature. In urban and suburban areas, this collective rise causes “heat islands,” or average air temperatures that become notably higher than those of surrounding areas. Cool roof systems reflect solar heat and radiate it back into the atmosphere; this technique helps to prevent heat islands and create a cooler indoor ambient temperature, as well as reduce the strain on the electrical grid during peak power usage times and lower individual energy costs.

I live in Florida. What are my options and how do I choose?

There are plenty of options when it comes to building materials; it can be a balancing act to find the most cost-effective match for you. When weighing your roofing options, there are several factors you will need to consider. These factors include:

Energy savings
Most homeowners with cool roofs enjoy lower energy bills throughout the hottest months of the year.
The money you save can depend on the climate of your area, your AC system’s efficiency, your current roof’s insulation (or lack thereof) and roofing materials, to start. Residents in areas of higher average temperatures can benefit from potential energy savings of up to 15%.
Additionally, certain Energy Star-rated reflective shingles can qualify you for federal tax benefits.

Size of your roof
The size of the project, as well as the ease of access to your roof, will be contribute to the final cost of installing your cool roof. Your certified roof installers will provide you with an in-person consultation that considers these factors in your written estimate.

New construction vs. retrofitting an existing structure
If your current roof is not a cool roof, you can opt to convert it by choosing to:

1. Re-cover the roof with a waterproof coating;
2. Retrofit the roof with certified reflective materials; or
3. Replace your roof – this may be your best option if your existing roof is in poor condition or is otherwise nearing the end of its useful life.

Note: Florida building code specifies that before re-covering an existing roof with new materials all old roofing materials must be removed if the existing roof has been damaged or has been re-covered previously. Check the building codes in your area to ensure compliance.

You can opt to include a cool roof in your new construction plans; talk to your contractor to discuss price, energy efficiency and other factors to choose your best options.

Asphalt Shingles

Asphalt shingles are the more affordable option for those considering upfront costs of a roof, but when it comes to energy efficiency, the most reflective (white) shingles are, at most, only about 30% reflective. They are, however, still frequently used for residential projects due to their lower cost and easier installation.

Certain Energy Star-rated reflective shingles – such as Owens Corning Duration Premium Cool – can qualify you for federal tax benefits. As an Owens Corning preferred contractor, AKVM roofers are certified in all things roofing and can help you decide which materials are right for you, as well as offer free inspections to determine whether your roof needs replacing and making sure your structure meets current building codes.

Metal Roofs

Available in panels, sheets or shingles, metal has become one of the most popular roofing materials used in residential construction in recent years. Depending on the specific options chosen, a metal roof can be 70% or more reflective; this means that the structure will be easier to cool and money can be saved on energy costs. 

Note: Metal roofs have the added benefit of being hurricane-resistant, lightweight, and recyclable. They’re also much more durable than traditional materials, often carrying a lifespan of up to 50 years.

Reflective Roof Coatings (most reflective to least reflective):

White roof coatings
These coatings are opaque and contain polymeric materials and white pigment. Thicker layers of coating will make the roof that much more reflective. With the use of these coatings, roof surface temperatures can remain much closer to the ambient temperature than a non-coated roof.

Aluminum coatings

An aluminum roof coating usually consists of an asphalt-like resin that contains aluminum flakes, which creates the appearance of an aluminum sheet without revealing the asphalt underlayer.  Aluminum coatings can reduce indoor temperatures by as much as 20°F.

Roofing membranes

Made of fiberglass, felt or polyester, the membrane is attached with synthetic rubber, asphalt or plastic. Regardless of material, roofing membranes are strong and flexible, as well as waterproof, and can be topped with reflective pigments to increase energy efficiency. 

Single-ply thermoplastic membranes are flexible sheets of plastic (such as PVC – polyvinyl chloride – or TPO – thermoplastic polyolefin) that are heated to mold the sheets together and close off the seams. These durable plastic membranes are generally white (most efficient), though colored pigments can be added to facilitate the target aesthetic.

Single-Ply EPDM EPDM (Ethylene Propylene Diene Monomer), favored due to its ability to be easily repaired, is known for its multi-climate flexibility, and is usually either black or white in color.

Clay tiles

Clay tiles are a popular cool roofing material in hotter climates for their high reflectivity (50%+) and thermal emittance (up to 86%). Tiles are exceptionally durable as well as 100% recyclable, and are available in an extensive range of colors, making them aesthetically ideal to many hot-climate homeowners.

Pigmented coatings
Substantially less efficient than white coatings, these colored shades are commonly used in residential projects to create a desired aesthetic.

Final thoughts

With many choices and considerations involved, upgrading your roof can seem like a daunting task, though it doesn’t have to be. Your roofers at AKVM are thoroughly versed in modern roofing options and can make excellent recommendations so that you end up with a roof that’s just right for you.

As this tech continues to evolve, we’ll see even more options and customizations that will make having a cool roof desirable and attainable for every homeowner. Ideally, more and more homes will adopt this energy-saving technology as it increases in popularity and affordability.

Questions?

Call the experts at AKVM at 941-727-3996 for more information.