Well, it appears as though my 2017 36RL is in need of caulking. I would like to go on record as saying I hate to do caulking. That said, I wanted opinions about the type of caulking I should use at the point where my roof meets the gutter.. I have both Geocel ProFlexRV in Clear (GC28100) and Dicor Cap Sealant (351CST-1) in Tan. I believe I have a TPO roofing membrane. In the back of my my mind I seem to recall from one of the RV rallies hearing that we were not to use Dicor products on a TPO roof. At the point where the roofing meets the gutter is it the same material as the roof itself? It is a rough material where the roof itself is smooth. Donít know if I explained myself very well.