(12-30-2015 12:56 PM)GoodOwl Wrote:  On the left side of the roof they are placing a white rectangular material. I'm wondering if this is the final roof covering or if there will be a gravel roof covering?

Also, its hard to see any drainage channel/intakes from the middle of the roof but I'd guess there'd have to be something to handle the rather substantial rain Houston can get at times?

The white rectangles are probably "tapered foam" that is used as an insulating underlayment for a modified bitumen upper surface.
There will be alternating layers of hot tar and thick roof felt, and the upper surface will likely be felt with a layer of white granules embedded in it.
Because the roof itself is sloped, the foam doesn't really need to be tapered - it could all be the same thickness.

As far as run off, I would venture that the central area is or will be sloped to the rear, so that the water pours off outside of the bowl.