Reflectivity: "What is the relative reflectivity between Galvalume and a metal ..." - Robert Smits (7/18/2012) | Energy Efficiency

What is the relative reflectivity between Galvalume and a metal roof coated with a reflective substance or color? Do you have a web site where I can research this? We are getting ready to re roof a 36 yr old home with 12 yr old asphalt shingles and also building a Metal storage building/workshop. Thanks, Bob	Robert Smits 7/18/2012	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/17623/find/
Robert, Thanks for the question. Galvalume has a relatively high solar reflectance, in the neighborhood of 50%. Typically only whites and light colors have that high of reflectance. ENERGY STAR lists values for many roof products at this web site.Select the last item - Qualified Roof Products. http://www.energystar.gov/index.cfm?c=manuf_res.pt_commercial#roof Regards, David Stermer	David Stermer 7/20/2012	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/17624/find/
We're getting a metal roof. We know that we want plain old white for the color to reflect as much of the light and heat as possible. Other than the paint color what else should we be looking for in a product or coating that will help reflect as much heat and light as possible?	Guest User 5/1/2013	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/17625/find/
White will be most reflective. However, especially if you live around a lot of trees, white will not stay white for long. If tree sap lands on it, that sap will hold dirt and can even support biological growth. With today's reflective pigments which help to make even dark colors meet Energy Star standards, I feel that folks do not have to have a white roof if they do not want one. Also, for enhanced energy efficiency, re-roofing is the time to take a look at ventilation and insulation as well.	Todd Miller Isaiah Industries, Inc. 5/2/2013	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/17626/find/
I wouldn't, personally, own a white car or roof. Shows dirt to readily like Todd said. The reflectivity performance is built into the paint as well as the colors. Get the color you want and I am sure they have high reflectivity options. Where is the home located, how is the attic vented, etc, etc.	Eric Novotny An informed customer is the Best Customer! 5/2/2013	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/17627/find/
One important factor - While Galvalume is much more reflective than painted, it doesn't release heat very quickly. So while a white or offwhite painted metal roof isn't as reflective, it will release heat much faster than a more reflective Galvalume roof. This is why light colored painted roofs have a better TSR (total solar reflectivity) rating than Galvalume. In my opinion, a light colored metal roof will always outperform a Galvalume roof in energy savings unless you live in an extremely cold area like some parts of Canada.	Nate Libbey 10/24/2013	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/17628/find/
Good information Nate. We might disagree on the performance aspect of things regarding the roof and how much of a performance impact it should have but that is good information on the Galvalume vs. Painted TSR ratings.	Eric Novotny An informed customer is the Best Customer! 10/25/2013	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/17629/find/
I am about to replace my Decra roof. It currently has a lighter grey color and my wife and I both like the black shingle color but living in DFW, Texas, we are concerned it will increase the heat in our attic during the sunlight hours. I can't seem to locate the answer on the impact of color choice for the stone coated metal roof. Being a larger 2 story home, my roof stays in direct sunlight most of the day. We have been told there is minimal impact and I understand that ventilation also plays a large role, but when comparing the same ventilation structure, does the darker colors increase heat within the attic and if so, is there a an estimate of what the impact difference may be?	Scott Norris 2/19/2018	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/22850/find/
I would suggest checking with Decra but chances are the current roof has solar reflectivity in the 20% range and the new roof will be more around 5%. Just my guess based on some assumptions. You will steel benefit from whatever attic ventilation you have (perhaps see if it can be increased) as well as by the thermal break created by the airspace between the metal shingles and your roof deck. I really would not expect a huge drop in energy efficiency. There will be some drop but I have no way to quantify it. I am sorry.	Todd Miller Isaiah Industries, Inc. 2/20/2018	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/22853/find/
We are trying to decide between Dark Bronze and the Dark Charcoal Grey. The emissivity and reflectivity is approximately the same for both. In regards to fading, which one fades more or least between these two colors? Thanks in advance.	Thais Fitzgerald Dark Bronze vs Dark Charcoal 4/23/2018	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/23054/find/
The lighter color would, in theory, be less prone to fading.	Eric Novotny An informed customer is the Best Customer! 4/23/2018	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/23056/find/
I'm confused. Does an unpainted metal roof reflect or absorb heat/sunlight? Would painting it a white, elastomeric (?) "cool" paint" make my house cooler? I have a corrugated metal roof, unpainted. The top floor of the house can really heat up in the summer, but I did not think it was because of the roof. I thought the roof, reflecting so much sunlight, already keeps my house cooler than not. No? Before I put on solar panels, someone said I should paint the roof with "cool metal roof paint" first, and so avoid installing air conditioning. Is that right? --anticipating heat waves in Los Angeles, re. global warming. I would like to make a decision about Paint or Not. Thanks for any help.	Sarah E Starr 3/7/2019	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/24102/find/
What is the construction of the home/roof assembly? Warm air is less dense that cooler air so every house is going to be warmer upstairs in the summer. Just depends on where the heat is coming from is all.	Eric Novotny An informed customer is the Best Customer! 3/7/2019	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/24103/find/
Thanks for giving the source about reflective substance.	peggydyer 5/10/2019	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/24262/find/
I am in the process on replacing a 20+ year old asphalt shingle roof on my home. Will any metal roof regardless of the color be more energy efficient that what I currently have, just because its metal vs. asphalt? I am selecting between the Sierra Tan (R35, E.91, SRI 39.1) and Sandstone (R51, E.9, SRI 59.8). The Sierra Tan will look much nicer with my light moss green siding and tan gutters and trim. I would like to understand just how much of a energy efficiency difference there is between the SRI 39.1 and 59.8? I want to make the most "green" option I can but I'm not crazy about the lighter color. Can someone help me understand just how big of a difference there is between what I have (old cheep asphalt) and my two metal color choices? Does it really make that bit of a difference between the lighter tan vs. the darker?	rkitt RKitt 6/14/2019	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/24325/find/
Your current shingles probably have an SRI of under 10. The Energy Star requirement is 25. Personally, I'd choose the color you like best. Thanks so much for considering metal!	Todd Miller Isaiah Industries, Inc. 6/15/2019	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/24326/find/
I am installing new solar panels with a 30% gain from roof reflectivity. Over time...galvalume or white most reflective?	Gerald Walker Solar 12/20/2020	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/25291/find/
Gerald, The Galvalume will eventually weather, which will dull the "shine". This will reduce the reflectivity. The reflectivity of a high quality paint, can be affected by dust but that can be washed off, to return the luster to the painted surface. The white painted should preform better, longer.	Robin Anderson 12/21/2020	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/25292/find/

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