Hi,
Just purchased 1989 Winnebago with some leaks in cab and in rear bedroom closet. After investigating the multitude of products and needing to cover seams and many years of tried solutions, I used bott the 3 " and the 6" rolls. the 3inch did the trick for the front cab area and the 6 inch was necessary for the rear seams. Looks like a great product if used properly.
Howard Gluck