diplomat roof seams

[Walker]

I bought a 2007 diplomat and have been slowly working the bugs out.  I am starting on the roof, but the p/o has done some repairs(?) and I am not sure of how the factory sealed the roof.  The caps have some type of foil tape, butyl, dicor, silicone, and some type of mastic brushed over all of it. It is a mess.  Does anyone have a picture of their cap joints from the factory? What about the curbside awning mount?  

 

[hex_nut]

It really does not matter how the factory sealed it.  What matters now is how you are going to seal it so there is no more water intrusion.  Years ago I bought a motorhome that not only had cap seams front and back, but also had full length seams along the edges of the roof (terrible design).  It had multiple layers of "stuff" that had been applied by the PO, all without any real success.  The key to repairing those kinds of botched hatchet jobs is adequate removal and cleaning of the previous "stuff".  I used a circular wire brush on an angle grinder to remove the Dicor sealant, silicone caulk and whatever else had been used (and, YES that is a messy job) .  Various solvents were then used to remove any trace of caulk and adhesives.  I applied 4" wide Eternabond tape to the cleaned surface pressed down with a small metal roller (Eternabond is pressure sensitive.)  I then applied a very small bead of self-leveling Dicor to the edge of the Eternabond tape to insure that wind and weather at highway speeds did not cause the edge of the tape to peel up. That is as close to a "permanent" repair that I know of on RV roof seams.  

Good luck on your repair.