My old Holiday Rambler Aluma-Lite has an (take a wild guess) aluminum roof. I kinda' like it because rubber roofs (if they know rubber tires will fail in 10 to 15 years from exposure - what made them think a rubber roof was a good idea) or fiberglass (fg gets old and cracks - some cosmetic some critical) have issues. Aluminum roofs do have inherent issues also, not the least of which is you feel like you're walking on a huge beer can.
Although I did not have any active leaks, I can tell where there have been some small ones before. I had decided I did not want to do all of the work on the inside only to end up havng it ruined by water intrusion... plus it really puts a damper on things when water is dripping on you as you are trying to sleep, read, play guitar, whatever...
I also knew I had to replace the old roof storage pod. It was cracked and worn out as it had been used to carry firewood. There was also some funky satellite tv dish setup and old cracked AC shrouds that all needed to go.
So, before doing a thorough cleaning, I cleaned and taped the seams with the Dicor seam tape. Neat stuff, almost like a putty on one side that, after the sun has worked on it for a day or two, seeps into and conforms to the seam to seal it.
Removing the old pod required Dremeling cut-outs where the screw attachment points were and prying the pod off because of all of the silicone the PO had used to fasten and seal the pod. Once that was done, I filled the screw holes with 5200, seam tape and tabs of fiberglass and resin.
Once the pod holes were filled, I hosed down the entire roof with house cleaner - Krud Kutter - and scrubbed with a broom. Just doing that made the roof look 100% better. But I could also see evidence of hail storms the old gal has seen.
I covered the whole old pod area with three layers of fiberglass (roving sandwiched between mat) to reinforce the pod mounting area. (Sanding, smoothing, etc rolling out a layer at a time). I have another to go back in its place.
Cleaned the roof with KK again (the coach got a bath also) for the last step to be ready to paint.
I had bought a 5 gallon bucket of roof coating from the same folks I got my floor coating from - Armor Garage. (No, I'm not affiliated, compensated, etc - I just like their stuff and their people/service.) The milspec roof coating material can be rolled or sprayed on, only needs 24 hours without rain and is guaranteed not to breakdown/leak for 12 years. Heck, I don't have that kinda' guarantee on me.
Applying the stuff was the tricky part - it was windy and the roof coating material is like liquified 3M 5200... and like 5200, it had a mind of its own and wanted to go everywhere if I wasn't careful. But I was able to brush in the edges and roll on the rest of the roof without too much getting away from me. I could just see the stuff filling in all the little nooks and crannies and leveling out little hail pocks. Cool...
I've now got two coats on (recommended), and I think I have enough left over for a third coat which I'll put on as well.
I can already tell the bright white coating is helping the coach be a little cooler inside and I bet it will help with the sound/noise resonance going down the road driving a huge beer can. Plus, I'm SURE I don't and won't have ANY leaks from the roof.