Most flat roofs aren't actually flat; they slope slightly to one side (a 1/4 ... Do this at least once every month or two, more often in the fall when leaves fly around. While you're at it ...

“Compared to previous research on flat roofs, we saw the same type of effects by the cavity distance,” Stølen added. “The main difference would be that with the sloped roof we experienced ...

“In the roofing world, we recognize a flat roof to mean that there’s still at least a two per cent slope,” says Russell ...