Who Wants a Cool Roof?

Does anyone else out there get annoyed in the summertime when they see a huge flat retail building with a black-top tar roof, and think, “That’s hot.”

I start wondering – how much are the owners paying for air conditioning? A lot of these buildings are quickly constructed with cheap steel and little insulation. The black tar roof is quick and cheap and simple. It’s also really hot in the summer time. Black tar can get up to about 175 – 200 degrees Fahrenheit on a hot summer day.

I understand that when a business starts up, they don’t have very much capital, and that they need a facility quickly and cheaply.

But it turns out there are a lot of low cost additions or alternatives to black top roofs that have a positive return on investment within a couple of years in energy costs. Couple this with the fact that a more efficient roof can allows a building to reach the same level of cooling with a less powerful (cheaper initial cost) air conditioning unit, and you’ve got yourself the makings of a good idea.

Energy Star has already started working on this one. They have certified several types of Cool Roof technologies. They have painted metal roofs, white ceramic, and many other options. They’ve also designed thin paneling that can be installed overtop an existing roof with no structural changes required.

A white roof can be 75 to 100 degrees cooler than the same roof in black.

This also helps out with the Urban Heat Island effect, which contributes to greater energy needs in urban areas due to higher temperatures caused by more dark materials and less vegetation than rural areas have.

There’s also a market for personal homes. However, sloped roofs don’t see as much of a benefit from improved materials as flat roofs. This is mostly because the amount of sunlight hitting a sloped roof is less than that of a flat roof. Further, sloped roofs usually have better insulation and ventilation that make the benefit of a cool attic less crucial. In most houses there’s a crawl space of some kind on the top floor, whereas in a flat roofed building, the top floor is usually within inches of the roof.

Still, if your home is in a warmer sunny climate, there’s still a sizable cost savings to choosing a lighter colored tile than a darker one. But if you’re like me, and live in a cooler cloudy climate, then you’re better off insulating the space between your living space and your attic, or planting deciduous trees on the Southwest and Southeast corners of your building. (That’d be Northwest and Northeast for people in the Southern Hemisphere.)

All that said, next time I’m in the market for a new roof - a.k.a. no time soon – I’ll be looking into the energy efficient options.