Even a water-tight roof can leak energy. In the summer, hot exterior air can penetrate; in winter, warmed interior air can leak out. The cost of this energy loss is a significant roofing issue. Polyurethane sprayed foam roofing: A sprayed on polyurethane foam roof provides the highest R-factor of any roofing material now in existence... resulting in 25-30 cost savings, and less wear and tear on...