Non SRI compliant material over Excellent SRI material

Thanks tristan....your are right....but say if we ponder over above methodology a little further... (please correct me if I am wrong in below assumption) Now we know that the SRI of a material is its ability to stay cool in the sun by reflecting solar radiation and emitting thermal radiation, in our case the underneath thermal insulating polystyrene board(with requisite U R values) will not experience any exposure to sun and hence its reflecting properties will not come into picture. Now the top most layer( gravels) are exposed to sun, due to its poor reflecting properties(owing to its dark color) there'll be considerable amount of temperature gain and consequent cooling by radiation( emissivity), here the heated-up gravels though would be able to transfer its heat to the surrounding upward space(air) but won't be able to transfer heat through underlying polystyrene board( due to its requisite R & U values)...and hence there wont be any heat gain by underlying room. But since the surrounding air at roof would get heated up(from radiating gravels) which then would be used as intake by FAHU, this will drive extra energy from FAHU.