The National Oceanic and Atmospheric Administration (NOAA) reports that July of 2019 became the hottest month on record for the planet. The record temperatures shrank Arctic and Antarctic sea ice to historic lows.

Solving the grave issue of global warming might not be something you can do by yourself, but you can decrease the temperature and energy usage of your building by choosing the right exterior colors for walls and roof.

Hot Roofs

According to the US Department of energy, the same philosophy of wearing light colored clothes in the summer to keep us cooler works on a building’s roof. It’s because light colors reflect rather than absorb solar energy.

A conventional roof is often the hottest part of a building. It can be 50 degrees hotter – or even more depending on the ambient temperature and the amount of sunlight. Meanwhile, your air conditioning is working harder than ever to counteract all of the heat the roof is absorbing. That’s if you have air conditioning for your metal and steel building.

The easiest way to cut down on the amount of solar radiation your building absorbs through the roof is to use material with a light color.

The Science of Color

It’s noon on a clear day. The amount of light landing on your roof is equal to a 100-watt light bulb for every square foot of roof that you have. That sunlight is made of three basic elements:

  1. Ultraviolet light
  2. Visible light
  3. Near-Infrared light

The average dark colored roof absorbs much of the ultraviolet, visible, and near-infrared light spectrums. A light colored roof reflects much of the near-infrared light. The difference is that this is about 35 percent of what’s reflected instead of absorbed.

White is the best color for a roof that can’t be seen from the street. A clean white roof can reflect up to 80 percent of the sunlight. It will stay about 55 degrees cooler than a light-colored roof.

But even a gray light-colored roof is an improvement. It’s reflecting more than 20 percent of sunlight.

Covering the Spectrum

Our steel and metal DIY building kits offer you a wide variety of choices to help use the science of color for temperature control. You’ll work with a Miracle Truss® specialist to pick color options for the steel roofing, siding, and trim for your building. Check out our color selections.

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