0088 Flat roof drainage systems
0089 Inverted roof membrane assembly
0090 Built-up roofing membrane - four-ply
0091 Damaged and patched flat roofs
0092 Blisters in built-up roofing membranes | 0093 Flat roof alligatoring

0094 Gravel erosion (scouring) on flat roofs

0095 Ridging and fish mouths on flat roofs

0096 Ponding on flat roofs |