Most of my house (located in Toronto, Canada) has a flat roof with a reasonable run off. It was built in the 20's and the roof is BUR with various layers added over the years. Some recent damage got me looking at the roof in preparation for winter. When I peeled back the membrane (looked like old ungranulated torch on), I noticed all the fiber board (cover up) boards were soaking wet. My question: is it worthwhile taking off all the wet fibreboard and replacing it with 1 or 2" polyiso and then recovering? Or should I just replace the fibreboard and recover with granulated torch on or roll on?
Thanks in anticipation.
Jimbo