Frequently Asked Questions

Does white roofs reduce interior temperatures in the winter?

Studies show that the effect of a white roof in the winter would be minimal since the sun is already at a lower angle and passing through more atmosphere during the winter reducing sun exposure on your roof.

 

Can painting rooftops white really make a difference?

Yes! "Steven Chu, the U.S Secretary of Energy and a Noble Prize winning scientist, has said that painting roofs white or another light color would help to reduce global warming by reflecting sunlight back into space —it would be like removing every vehicle from the planet for 11 years."

Source     Date: 28 December 09

 

Why White? What's the science behind that?

"The Earth has an albedo of 0.29, meaning that it reflects 29% of the sunlight that falls upon it. With an albedo of 0.1, towns absorb more sunlight than the global average...

Painting all roofs white could nudge the Earth's albedo from 0.29 towards 0.30. According to a very simple "zero-dimensional" model of the Earth, this would lead to a drop in global temperature of up to 1 degree C, almost exactly canceling out the global warming that has taken place since the start of the industrial revolution."

Source     Date: 28 December 09

 

Can you paint over tar?

Yes! Since most flat rooftops are coated with tar and gravel, painting over tar is a very common especially in NYC. All that is required to properly paint over tar is a primer with an asphalt base. After the primer sets you can coat it with white roofing paint.

 

What else can white roofs do for the environment?

White Paint actually contains titanium, which has natural abilities to filter the air .

"Better known as a pigment for whiteness, titanium dioxide can clear the air because it is an efficient photocatalyst: it speeds the breakdown of water vapor by ultraviolet light. The results of this reaction are hydroxyl radicals, which attack both inorganic and organic compounds, and turn them into molecules that can be harmlessly washed away with the next rainfall."

Source     Date: February 02