Born Free Leap'n Lions RV Club Info & Discussion Forum

We have a 2016 Royal Splendor on a Ford F550 chassis. Yesterday, when driving through the rain, water dripped onto my left knee through the handle mounted on the door frame. This has happened before and I thought I had plugged the leak. When we got home, I checked the roof of the cab and found two cracks in the metal cab roof where the fiberglass nose cone of the coach is caulked to the cab roof. Each crack is about 1 1/2" long. Attached are pictures showing the cracks and their location (pink arrow).
I'm thinking of just caulking over the cracks with self-leveling Dicor. I'll ask the Ford dealer for suggestions but if you have some, please let me know.

Detail photo

Those look like stress cracks to me. Possibly from motion between the fiberglass cab-over and the metal roof. I only say this from my own observations of the cab over of my E450 chassis bobbing up and down ever so slightly when rolling down the road. I'm sure this is normal but it caused me to think that some really big forces are at play in the method the roof and cab are attached.

I think you have metal fatigue from this same bobbing motion. The standard trick to stop a propagating crack is to drill a small hole right at the end of the crack. I would do this before you seal it up. Something in the size range of 1/8 to 1/16"" should do and still seal up OK with whatever material you use on the rest of the crack. Just be sure to get the hole all the way at the end of the crack or it might start to expand again.

BTW. This shouldn't have happened. I have had the interior headliner apart in my coach and the metal cut out had a pretty ragged edge. I wouldn't be surprised if your cracks could be traced back to an especially rough cut in the metal roof allowing them to get a start.

Good Luck