About six weeks ago we had our roof in the back of the house torn down to the rafters (?) and a new roof put on by a supposedly reputable roofing company. This part of the roof is flat (although it has a very slight slope to it). They claimed the best roofing material for that kind of roof was rolled roofing with a blowtorch put to it. However, now there is a ton of loose "gravel" from the roofing material; it is getting into the gutters and also just lying around on the roof waiting to be washed into the gutters. I was on the roof this weekend sweeping up leaves and also swept up a ton of this loose gravel. Is this normal? Is there some kind of coating I can put on the roof to make the gravel stick? I don't want the roof to come apart after it's just been installed. I paid a ton of money for the roof. Thanks.

Thank you