We installed this flat roof near Harvard Square in Cambridge, Massachusetts in the summer of 2010. The installation consisted of four separate roof sections on different levels of this house, which at the time was undergoing major renovations inside and out, including total new insulation in walls and between roof rafters, a new heating system with radiant floor heat, new energy efficient windows, and a new IB PVC flat roof (which we installed of course).
The old rubber roof was leaking and we had to remove it, including the wet roof insulation. We installed a new 50-mil white IB Flat Roof, with 4 inches of tapered insulation (4 inches at the highest point and 1 inch at the lowest level). The tapered insulation system was utilized to eliminate ponding water on the two bigger sections of the roof. At the deepest point, there was as much as 2 inches of ponding water, and a puddle with at least 12 feet diameter. This ponding water caused both roof leaks and the roof rafters settlement.