I see no responses to you so far. Welcome to the forum. I am not familiar with your coach at all or how its roof is constructed but I would expect that the roofing material (if EPDM or TPO) is probably glued down to the plywood top and was probably installed as one continuous roll when built. So rolling back glued roofing is likely not an option. Sounds like you have two water damaged areas; around the shower dome and then a second area about 30 inches away. If the roof plywood layer is soft/rotted in either area, it should be repaired (remove the rot layer and fill with wood epoxy as a minimum) because any new roofing patch/repair will not stick to rotted submaterial; plus the shower dome has to have solid material to screw back into; and there is the safety issue for future roof walkers. I am not sure what size roofing patches (like eterna-bond) are available so you may want to check that out (compared to damaged area) or have a reputable RV shop or Mobile RV tech investigate and give you a price to properly repair or suggestions for doing it yourself.
__________________
|