# Self-adhering modified bitumen roll roofing



## FLHomeInspector (Mar 30, 2018)

When installing modified bitumen roofing does it have to be installed on a flat, clean substrate? I just inspected a roof that was installed days ago over sagging OSB sheathing.






It had many issues but where the sheathing was sagging between the joist the bitumen did not seal to itself. It is highly doubtful if the surface was rolled or if there is even a base sheet was installed. The cap sheet is gapping at the joints.


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