Default Gravel SRI Values

Light colored gravel is going to count against you whether you use the LBNL data or not. Using the LBNL number and uploading a screen capture / download of it will at least give you a number to plug into the formula. It is worth a shot but I would be prepared to run it as a '0' in the formula. The online document makes this an easy calculation to run.

I really don't think they will let you do that because that study says the values for the ballasted roof are "approximate." Can you bump up the SRI of any other roof area? Using the weighted approach helps me on a lot of projects. See LEED interpretations #2450 and #10113. #10113 says "to determine the SRI value for materials that do not have recognized standard values (e.g. new gray concrete) the materials must be individually tested." LEED Interpretation #2450 says ballasted roofs need to meet the SRI requirements. Anyone ever rented an emissometer? http://surfaceoptics.com/products/reflectometers-emissometers/et100-thermal-hand-held-emissometer/

I know this thread is a few months old now, but I'm hoping there may be some new information out there, or others still interested in the topic. I understand that the LBNL test results on gravel are approximate, and there is the issue of how gravel, given it's irregular shape, can cast shadows on itself, but I'm not sure I understand the reasoning that, in lieu of approved test results on the gravel used on any particular project, you must consider the SRI value to be zero. If I took a random sampling of the GBCI reviewer's out to the desert at high noon and gave them the choice to walk barefoot across a patch of dark gravel or a patch of white gravel, would they say it doesn't matter to them because the test results are only approximate? Surely there should be some default number, a worst case average, that would be acceptable rather than zero.

I just found this post and although it is several years old at this point, I'm interested in knowing if a light colored gravel parking lot would help/contribute under the LEEDv4.1 SS Heat Island Reduction credit (use paving w/ min. 0.33 SR). We'll do the calculations but does anyone know if this is a "no-go" with the GBCI reviewers? I would think that it would be a no-brainer that light colored gravel is about equal to light colored concrete when it comes to SR values... and is certainly more sustainable than asphalt. Help, anyone? Thanks!

Yes, light colored gravel does contribute, as long as you can obtain the SR value.