If you do a search on Eternabond, I think you will find a lot of information. Many on the forum, including myself, have used this stuff.
I washed my coach (including the roof), cleaned the roof seam area with spray brake cleaner, then applied the tape. I cut the 4" roll into 2" wide lengths and used a wallpaper seam roller to help press down the tape.
The stuff really sticks and I'd say it is pretty much a permanent fix.
'07 Country Coach Allure 470 Siskiyou Summit #31578, Cummins ISL 425; 2014 Ford F150 toad; Air Force One Toad Brake.
Glen Allen, VA; Smith Mountain Lake, VA.