http://nseej.com/رسائل/-142920/ Thermal cycling and water, especially ponding water erode the mineral cap leaving the black sheet to absorb warmth and UV radiation. Worn cap sheet cracks and checkers. The dried roof supplies can no longer transfer so the seams separate at an accelerated price. Uncovered fiberglass mats and felt grow to be dried out and rapidly deteriorate. Sat, 28 Jun 2014 22:22:37 UTC en