I'm about to replace the original plumbing roof vent on our 2010 EggCamper
with a Camco replacement vent kit (original is chipped, cracked, brittle and chalky). The kit comes with butyl putty tape for mounting, then the instructions say to apply a roof coating round the flange. I was planning to use Geocel ProFlex sealant on the flange, but the local camper repair pro convinced me to buy some Dicor Self-leveling Lap Sealant for the job instead. Now I'm wondering if the Dicor really is that much better or if he just wanted to make another sale. Any recommendations based on personal experience? Another recommendation he made was, if the base of the old flange is still tightly adhered to the camper shell, to just cut the chimney part of the old one off, leaving the old flat flange, and then mount the new kit on top of the old flange and cover the whole thing with sealant. Seems like a short-cut, for sure, but at what cost down the road. Anyone ever heard of such a short-cut - mounting a new vent on top of the old flange?