Q.Roof-Top Garden Flooring
I am building a roof-top garden. The roof is structurally sound, but I need to cover the area with something to protect the existing external rubber roofing. I have heavy rubber mats with holes for the garden area (often found in commercial kitchens), but have had trouble finding something for the walking area. Would prefer something light colored (the roof is black and heats up to something horrible during the summer). Any material or product suggestions?

Try your local Home Improvement store. There are several products on the market that are of rubberlike or wood construction that fit together like puzzle pieces. The experts there can probably tell you which products are best for allowing you to use your rooftop while preserving the roofing material.