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I often wonder why nobody paints their roof white. I see all this black asphalt soaking up heat on roofs in the south and think that everyone must be crazy.
by CompelTechnic 8y ago
I often wonder why nobody paints their roof white. I see all this black asphalt soaking up heat on roofs in the south and think that everyone must be crazy.
- zeroxfe 8y agoYou'll see a lot more white roofs in hot countries than cold ones. Can't repaint just for the summer here in Canada :-)
- goda90 8y agoIt'd be interesting if we saw an e-ink like tech that can switch the color of paint with a single electrical signal and not need to stay powered the rest of the time.
- opportune 8y agoor the ink could change color based on temperature/light exposure
- bluGill 8y agoCold climates generally have insulation meaning roof color isn't as significant as in warmer climates. Also cold climates also imply snow which brings us back to a white roof.
- HarryHirsch 8y agoA few years ago they had a program in Philadelphia to do just that. Too many elderly people dying due to heat-related illnesses.
- sjg007 8y agoYou do that in Arizona, white or silver.
- benmanbs 8y agoFun fact - in Bermuda they paint their roofs exclusively white. Though that isn't necessarily for heat conservation, they use their roof to catch rain water for household use.
- orev 8y agoIt is crazy. But houses with dark roofs look better, so they sell better. And replacing a roof is very expensive, so no one is going to do that on a new house just for the heat. Further, many new construction houses are in HoA neighborhoods, and HoAs don’t like people to be unique because it “spoils” the uniform look and “decreases” property values. It’s the system working against us. The only solution would be to codify requirements in building codes.
- woofyman 8y agoWhite roofs stain and get dirty. Especially if leaves get on them.
- orev 8y agoLighter colors, even if not white, would still reduce absorption and increase reflection. A middle-gray would help, and possibly something with a color tint to it.
- lucb1e 8y agoHome owner Association, in case anyone else is wondering.
- reaperducer 8y agoIn a similar vein, I've sometimes wondered why roads aren't a lighter color. I drive on some recently paved roads and they were all paved black. Seems that if we mixed the asphalt with a small amount something light and unwanted (plastic bottles?), but light in color, we could put a dent in both the garbage problem and the heat absorption problem. Doesn't have to be full white, as that would glare worse than dark black. But a few shades lighter could help some.
- taxicabjesus 8y ago> In a similar vein, I've sometimes wondered why roads aren't a lighter color. Years ago the freeway maintainers were applying rubberized asphalt to the freeways in the metropolitan Phoenix area. The newly-rubberized freeways were very, very black. "Brilliant, just brilliant", I thought. Some time later I read that while rubberized pavement gets hotter than plain asphalt during the day, it cools much, much quicker at night. The article had infrared aerial photos of the Phoenix metro area pre-rubberized freeways and post-rubberized freeways. Before the project the freeways were all lit up. After the rubberized surface was applied, the freeways were entirely black on the infrared photos. Rubberized asphalt, applied to Valley freeways to minimize noise, has an unintended benefit: It's cooler at night than other pavement, according to the Arizona Republic. That's because air holes constitute 20 % of rubberized asphalt, said Kamil Kaloush, an assistant professor of civil and environmental engineering. Those pockets of air allow heat to escape, something that dense concrete can't do. - https://www.roadsbridges.com/rubberized-asphalt-cooling-phoenix-streets https://www.roadsbridges.com/rubberized-asphalt-cooling-phoe... https://en.wikipedia.org/wiki/Rubberized_asphalt https://en.wikipedia.org/wiki/Rubberized_asphalt
- mytec 8y agoLos Angeles is starting to paint its streets white. https://www.popsci.com/la-is-painting-its-streets-white-to-keep-city-cool?src=SOC&dom=tw https://www.popsci.com/la-is-painting-its-streets-white-to-k...
- dvirsky 8y agoWhen I was growing up (in a desert town) we had a house with a flat roof. When we bought it, it had tar based black sealant painted on top of it, and it was hell. The next year we covered it with white polymer based sealant, and the difference was huge.
- kimdotcom 8y agoAlso, in the US, ducted AC vents in the attic, and thr air handler in the garage. Although, minisplits have become more prevalent.
- briandear 8y agoRoll roofing in places like New Mexico is white.
- tomerv 8y agoIn Israel, where the climate is warm, almost all roofs are painted white. In fact, many buildings repaint the roof every summer, just to help lower the temperature for the top floors.
- csomar 8y agoI think they repaint the roof for rain insulation.
- csomar 8y agoMy guess is that if you are on a house with a roof you already have colder climate? (because the roof is for the snow). But it might not be the case for the US.
- HeyLaughingBoy 8y agoI'm guessing that you mean something other than "roof" because a house without a roof would just be an open box.