Sealing seams and the vents on a fiberglass roof

[Rbbauer]

I know this has probably been asked many times but I am a newbie. What is the best product to use to seal all the seams and vents on a fiberglass roof?

[Spk64]

Eternabond is a great product for that. Dicor for areas that does not use the Eternabond tape.

[Gary RVRoamer]

You want an RV lap sealant, e.g. Dicor lap sealant. Use the self-leveling type for flat surfaces and the standard (clinging) type for slanted or vertical seams. You can use a sealing tape, e.g. Eternabond or Dicor Diseal, instead if you like. It works well on reasonable smooth surfaces, but harder to get a good seal on curves or corners.