Thursday, August 4, 2011

Up on a Hot Tin Roof

I hope not - but we got the color chart from the roofing manufacturer so we can start the, what will probably be a lengthy, deliberation about what color our roof will be.


There are lots of color choices for standing metal seam roofs but the important part in choosing is the TSR or Total Solar Reflectance value assigned to each color. TSR is the sum of ultraviolet, visible and near infrared (IR) reflectance. Ultraviolet makes up 5% of the electromagnetic spectrum, visible 43%, and IR 52%. The 52% long near infrared wavelengths are invisible to the eye yet provide a significant portion of the suns energy heating the earth’s surfaces.

Yeh, aren't you glad someone else gets to run those calcs!

Here is what the Unpainted Galvalume looks like on a lovely pink, what I hope is beach house (our house will not be pink).


I really like this look and think it will go with the house well. Best of all its TRS is 68% which is one of the highest values you have have.

Re-Nest just did a great post about a cool organization that is promoting white roofs to reduce heat absorption. The White Roof Project is raising both money and awareness to turn dark roofs light. They have some great research available but the upshot is:




Black Roof White Roof
TEMP Outside 90°
Roof Temp 180° 100°
Inside Temp 115° 80°
Reflects Sunlight 25% 85%
Saves Electric Bill 0% 40%

Of course there a many other factors that a cooler roof influences but these are the biggest bang for your buck so to speak. And our house won't have A/C so we won't see any $ savings but we will be cooler and when you don't have A/C you will do whatever it takes to keep that place cool.

Back to my handy dandy color chart.

UPDATE - here is a good example of the color we are leaning toward, though its not set in stone yet.




2 comments:

  1. Did you pick a color?

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  2. I think we are leaning toward the galvanized look, its got the best TRS without going all the way to white which might not fit so well with the exterior we are planning. (Don't ask, exterior siding is another huge hurdle).

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