Installed the Maxxair fan, odd find

gaymeadowsman wrote:
there was no Butyl tape. It had the same caulk that was on the top side covering the screws and flange. I don't guess it is anything "wrong" with it,but of all the videos and how to's I had read they all had butyl tape under the factory install.

You're lucky. A lot of the sealants cure to be almost unremoveable, making it near impossible to remove whatever without damaging the roof. Good quality butyl tape (Dicor makes that, too) under, sealant on top. That way you can carefully cut through the sealant around the edges and easily remove whatever since the butyl won't act like a strong adhesive. That applies double for things with wide flanges, like the base for an antenna.