What are some of the characteristics that you should consider when choosing a roofing material? Your answer would likely include aspects such as cost, durability, brand, and of course, color. While all of these factors are significant, the increasing need for energy-efficient roofing systems has added one more important consideration: the Solar Reflectance Index (SRI). This index measures how well a roofing material reflects solar energy, making it crucial when selecting an environmentally friendly option.

While homeowners are usually aware of the price and durability of various roofing materials, we get many queries regarding the SRI, especially from new homeowners. 

To help you understand, we have created a detailed guide in which we discuss the SRI index, its importance, and how it connects with efficient roofing choices. 

What Is The Solar Reflectance Index?

The Solar Reflectance Index, or simply, SRI, measures how well a roofing material reflects sunlight and releases absorbed heat. In simpler terms, it’s a way of assessing how cool a roof stays when the sun is blazing. 

Why Is There A Focus On Cool Roofing?

Cool roofing has gained importance because it helps reduce energy consumption, lowers indoor temperatures, and combats the urban heat island effect — making homes more sustainable and comfortable.

To calculate the SRI, a scale is used that typically ranges from 0 to 100:

• 0: A standard black surface, which absorbs the most heat and reflects the least.

• 100: A standard white surface, which reflects the most sunlight and stays the coolest. Some specialized roofing materials can even have SRI ratings above 100, thanks to advanced reflective coatings.

The SRI also combines two factors: solar reflectance and thermal emittance. 

• Solar Reflectance: Solar reflectance measures how much sunlight a material reflects off its surface instead of absorbing it. It’s rated from 0 to 1, where 0 absorbs all sunlight (like black asphalt) and 1 reflects all sunlight (like fresh snow). A high solar reflectance means less heat absorption, keeping your roof cooler even on the hottest days.

• Thermal Emittance: Thermal emittance gauges how efficiently a material radiates absorbed heat back into the air. Higher values indicate better heat release. For example, materials like clay tiles have high emittance, allowing them to shed heat quickly, while some metals might retain more heat without proper coatings.

Why Does The SRI Matter To Your Roof?

The higher a roofing material’s SRI  number, the more likely the material is going to improve the comfort of your home. 

Here are some other reasons why the SRI is a number you want to pay more attention to when shopping for roofing materials:

Contribution In Energy Efficiency

A roof with a high SRI can dramatically reduce your cooling costs by reflecting more sunlight and radiating less heat into your home. This is especially valuable in hot climates or during summers.

While air conditioning may account for a significant chunk of your energy bills, by deflecting solar radiation, these roofs help lower indoor temperatures by up to 10 to 15 degrees, saving homeowners around 20 to 40% on summer cooling expenses. It also helps reduce the strains on your HVAC system.

Comfort

Ever noticed how some rooms in your house are hotter than others? That’s often due to the roof. A high-SRI roof can help maintain a more consistent indoor temperature, making your home more comfortable year-round.

Roof Longevity

Excessive heat can cause roofing materials to degrade faster. Roofs with high-SRI roofs stay cooler, which can extend the lifespan of your roof by reducing thermal stress and preventing warping.

Traditional dark roofs can reach extremely high temperatures on sunny days, causing materials to expand, contract, and ultimately, break down more quickly.

Environmental Impact

By choosing a reflective roof you’re doing your part to promote sustainable living. These roofs not only lower local temperatures, they also reduce overall energy consumption, which translates to lower carbon emissions.

SRI and Roofing Materials: What You Need to Know

Different roofing materials and colors have varying SRI ratings. Here’s how some common options stack up:

Asphalt Shingles

Standard asphalt shingles generally have low SRI ratings, as they tend to be darker and less reflective. However, many manufacturers now offer cool roofing shingles, which are specially designed to improve solar reflectance without sacrificing appearance. 

What Are Cool Roof Shingles? 

Cool roof shingles use advanced granules or coatings that reflect more sunlight, helping reduce heat absorption. Cool roofing shingles achieve significantly higher SRI ratings compared to traditional options. For homeowners who prefer the classic look of asphalt shingles but want the enhanced energy benefits that come with a high-SRI roof, these are an excellent choice. 

Here are some of the options: 

• CertainTeed Landmark Solaris®  Shingles
• Owens Corning TruDefinition Duration Shingles
• Atlas Pinnacle® Sun Shingles

Metal Roofs

Metal roofs are a standout choice when it comes to materials with a high SRI. Their natural reflectivity, combined with their durability, makes them highly energy efficient. The SRI rating of a metal roof can be further enhanced by using special reflective paints or coatings, such as those from Sherwin-Williams or Kynar 500. These coatings are engineered to reflect more sunlight and protect the roof from UV damage, giving metal roofs a sleek, modern look and outstanding energy performance.

Coatings and Technology

For both asphalt and metal roofs, reflective roof coatings can significantly boost the SRI rating. These coatings are applied to the roofing surface and are particularly useful for homeowners who want to upgrade the performance of their existing roof without a full replacement. Options like elastomeric or silicone roof coatings can improve solar reflectance and thermal emittance, keeping your roof cooler and prolonging its lifespan.

Also Read: 5 Best Cool Roof Coatings Of 2024 (Ranked) 

Best Roof Colors for High SRI Ratings

The color of your roofing materials also plays a large role in the SRI. Here are some of the top colors and why they’re effective:

White

The gold standard for reflectivity, white roofs reflect the most sunlight and have the highest SRI ratings. White also comes in various shades, providing subtle variations that affect performance.  

Light Gray

A more neutral alternative to white, light gray balances appearance with energy efficiency. You can find a light gray color in both asphalt shingles and metal roofing panels. 

Beige or Tan

These earth tones offer good reflectivity and blend well with many home styles.

Pale Blue or Green

These lighter shades provide moderate reflectivity and a unique, attractive look.

Metallic Finishes

Coated metals in lighter finishes, such as silver or champagne, can also achieve excellent SRI ratings.

While darker colors like black or deep brown are more traditional, they typically have much lower SRI ratings. If you love a darker roof, consider materials or coatings designed to improve reflectivity.

Also Read: Top 10 Metal Roof Colors To Know About

Find The Best Roof Replacement Company In Oklahoma! 

While the SRI might not be the first thing you think about when choosing a roof, it’s an essential factor that can make a big difference in your home’s comfort, energy efficiency, and environmental impact. Whether you’re drawn to the timeless look of shingles or the sleek efficiency of metal, understanding a material’s SRI ensures you make a smart, informed decision.
At A. Fricker Roofing and Waterproofing, we have trained professionals with years of experience installing cool roofing systems that utilize asphalt shingles and metal roofs. Contact us today at (918) 402-7167 to get started.