20 unusual ways to save money: Paint your roof white
Filed under: Home
Back in science class we (should have) learned that white surfaces reflect all visible light. For centuries, people living in sunny climes have taken advantage of that property to reduce the heat load on their property, by creating white roofs. White roofs reflect the sun's rays and can make a considerable difference in one's air-conditioning bill.
The state of California mandates white roofs on new commercial buildings to decrease the load on the electric grid and commensurate carbon dioxide emissions. The same benefit can be realized by homeowners in the sun belt. A recent study found that a 1,000 square foot home with a white roof could save ten metric tons of CO2. This could translate into a 10-15% drop in your air conditioning bill.
New regulations soon to take effect in California mandate energy-efficient covering on sloping roofs, too, including residential housing. If you're not a fan of white sloping roofs, though, don't panic. Since half of the heat in the sun's rays comes from the near-infrared, non-visible part of the spectrum, new roofing materials in traditional colors are available that still reflect these rays and meet the state's requirements.
I doubt that the savings will cover the cost of treating your existing roof material, but if you're in need of a new one, consider going white with a flat roof, or using heat-reflective materials on sloped ones. The cost of electricity is headed nowhere but up.
Reader Comments (Page 1 of 1)
12-17-2008 @ 10:02AM
Bob Lawrence said...
We now have the advanced color pigment technology that can be applied over an existing roof to cool the home.
A white 6 mil undercoat is used with a cool coat colored pigment then a clearcoat. Where a normal dark roof will have a temperature of 190 degrees on a hot day a cool coated roof will peak at 100 to 120 degrees.
The cool coating will reduce attic temperatures. Your air conditioner will have an easier job cooling your home saving considerable amounts of energy and lowering your your bill.
This process is so effective it qualifies for southern California Edison rebates.
for more information you can contact Western Roofing Systems at 1-800-766-8000 and ask about the Western "Cool" Roof Coating process
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12-17-2008 @ 12:20PM
Wallace Fisher said...
What can I do with an old fashioned red clay tile roof? Any coating available to save on energy, besides a white coating?
12-17-2008 @ 10:20AM
Tommy said...
My outside A/C unit went thru It's first motor in just 5 yrs. The reason i believe was from direct sun from 9 to 4 . I put a picnic table umbrella over the top about 4ft higher than the fan . I think this will let it run cooler during the 90+ days of summer.
Hopefully adding life to the 2nd motor.
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12-17-2008 @ 1:40PM
Edward said...
Would this work in an area that is NOT the sunbelt? In New England, would the summer energy savings in the summer exceed the heat you lose in the winter?
They really should come up with a roof material that changes color from white to black based on the temperature. That would not in principle be any different from the coffee mugs that change color Or those del sole shirts.
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12-18-2008 @ 11:30AM
Bill T. said...
I live in South Texas and have a major attic heating problem in the summer. Does anyone have experience with the ceramic based paint that can be applied over a asphalt shingle roof. I read about this product several years ago but cannot remember where. Thanks for any help...........
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12-18-2008 @ 10:53PM
John Hayes said...
Most places the heating bill is higher than the cooling bill over the year.
assume heating to 70 degrees and cooling to 80 degrees
They are the same if the temp outside is at 40 degrees the same amount of time it is 110 degrees as both mean you change the house temp by 30 degrees.
I have had to heat the house 50 degrees from 20 but never cool 50 degrees from 130
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12-21-2008 @ 4:55PM
ronald said...
it dont work for my house my flat roof is all white but theres a lot of heat in the closed patio so somethings up
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12-21-2008 @ 7:58PM
Barb said...
A brilliant idea... IF you live in a warm climate!
However, when you're sitting here looking out your window at a blizzard (as am I as I type this) and it's heating, rather than air conditioning, weather for MORE than 1/2 the year, this little tidbit isn't a whole lot of help!
My central air gets used 2 or MAYBE 3 months out of the year... the heat's on from October (I refuse to turn it on sooner) through April or May. So this tip isn't very energy-efficient for me.
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1-03-2009 @ 8:57AM
biochem39 said...
Personnally I despise AC. I use fans, they cost less to run and feel natural. Two decades ago when I lived in southern Florida during July and August I used fans. I still use them to this day
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1-04-2009 @ 8:28PM
DHTmama said...
Keep the sun off a dark roof in summer by surrounding the house, expecially the east and west, with deciduous trees (the ones that drop their leaves in winter so that the sun will warm the house.)
Put evergreens on the north side for wind block.
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1-07-2009 @ 12:11PM
patrick said...
There are other ways of keeping your house cool! If you have a pitched roof and are thinking of re-roofing check out Gaf/Elks COOL ROOF it comes in many colors (other than white) and reflects over 80% of the heat back up! If you want to see some of these roofs check some of ours out at www.aaroncarterconstruction.com
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