The Big Problem with Black Roofs

There is a lot of this blog dedicated to dispelling myths about old buildings and really building in general and today I’m gonna tackle a BIG one. This is more of a hypocrisy that is rampant rather than a myth, but just like faux shutters it is the pervasiveness of this that drives me absolutely batty.

This issue is the epitome of being pennywise and pound foolish and most homeowners don’t give it a single thought lest they realize how much this decision really costs them annually. So, what is the big deal? It’s the roof, dummy!

Black Roofs vs Energy Efficiency

As our society becomes more and more focused on energy efficiency in our buildings. We spend thousands of dollars to squeeze every bit of efficiency out of our homes with gimmicky products like vampire switches, outlet covers, smart plugs, and even LEDs that proclaim to last for 18 years but rarely last more than 3-5 years.

All the while we ignore the one part of our house that (for southern climates) causes the greatest increase in our energy bills. The roof. More specifically the color of our roof, and the “hottest” trend (pun intended) right now is a white house with a pitch black roof. They are everywhere.

Conventional roofs have usually been a mix of colors, but lately the trend of a pitch black roof to contrast with an all white house has been raging across the country. It’s beautiful for the eyes, but deadly to the AC.

Black is the absolute worst color you can choose when it comes to energy efficiency in southern climates. It absorbs every bit of the sun’s energy and pushes it down into the house below. It takes hours to cool down after sunset and makes air conditioners work overtime and die years earlier than they would have otherwise.

How much do these dark roofs cost us? According to Energy.gov “Conventional roofs can reach temperatures of 150°F or more on a sunny summer afternoon, sun. Under the same conditions a reflective roof could stay more than 50°F cooler.” Dropping the temperature to just a few degrees above the ambient outside air.

This equates to big savings since it’s your attic and roof that account for the lion’s share of cooling costs. Choose a cool roof option the next time your roof is due for replacement and you’ll notice significant savings right away. And the best part is that those savings don’t fade away over time like with replacement windows which become less effective each year. A cool roof is a long-lasting improvement.

What is a Cool Roof?

The color and materials you use on your roof matter. Just like the clothes you wear some materials are more reflective of the sun’s heat. Whites and light colors don’t absorb anywhere near the kind of heat that dark colors and black in particular absorb.

Put a black asphalt shingle roof on your house and you’ve just installed a solar heat collector above your attic that your AC will battle every single day. On the contrary put a reflective silver colored metal roof on your house and you can buy a smaller AC unit and have that unit last longer because your roof takes the sun’s rays and reflects them back into the sky.

The best cool roof option is actually a living roof, otherwise called a “green roof” with grass or other plants growing on them. These roofs keep the temperature almost at parity with the ambient air. If you can go this route then more power to you, but this not practical for most homes.

The options for the rest of us are so incredibly simple. Here are some great cool roof options:

• Metal Roofs – One of the most effective forms of cool roofing is a metal roof. Whether that is a 5v crimp, standing seam, or metal shingle roof these are extremely long lasting (50-100 years). Choose a silver or white color for the most cooling options.
• TPO (Thermoplastic Polyolefin) – This single layer roofing option for flat roofs is gaining in popularity. TPO is a bright white roof covering that is highly reflective, incredibly efficient, easy to install and can last 20-30 years.
• Cool Shingles – Most manufactures of asphalt shingles have cool shingle options with different technology and most importantly lighter colors that reflect more heat than traditional shingles. They are worth looking into because the additional cost compared to traditional shingles is negligible.

Trying to be energy efficient living in a house with a black roof is like driving a Tesla while towing a ton of bricks behind it. It’s completely counterintuitive and yet it happens every single day.

Ironically, the people in these houses are usually the ones clanging the most loudly that those of us living in our historic houses are wasting energy and need to change to be more like them. Facts are tricky things and I’m not in the habit of ignoring them.

What Can You Do?

The next time you are due for a roof replacement you should absolutely consider a cool roof option that works for your style house. Go with the lightest color you can find.

Metal will typically be the most effective and longest lasting option, but in most cases the cost of a metal roof is about two times the cost of an asphalt shingle roof. Your roof will last three to four times as long if it’s metal so in the end it is the cheaper choice if you plan on being in the home that long.

You may be thinking that a light colored roof won’t go with the current color scheme of your house. That may be true, but houses can also be painted. If you are passionate about cutting your energy usage then a cool roof with a modified paint scheme for the house is the best option.

Let me be clear that I am not faulting people for choosing a black shingle roof. I admit the style is a very distinguished looking. This is a bit of rant for me personally because I have had quite enough of the preaching by the black roof crowd about how those of us who drive pickup trucks or live in old houses are feeding the climate change monster they are trying to fight.

There are ways all of us can do better in this fight and swapping out that black roof for a cool roof option is a big way to win the fight. Let’s work together and remember we’re all in this together!