As bumpy told me on a recent Class A post, use Dicor. They have two kinds you probably need to use, the self leveling for use around vents and the non-sag that you would use around areas like the TV antenna, etc. There is a video on the Dicor website that shows you exactly how to do the roof and which type of Dicor caulk to use on which areas. The local RV shop wanted $700.00 to do the roof on my 2002 Itasca 32V class A, I did it for the cost of 4 tubes of caulk and my time (and I'm certainly not worth $700.00/hr.) Just my opinion.