About a year after we got our Montana I asked one of the local dealerships I was at (we were traveling at the time), what should be used on the roof. I'd never done anything with it the first year. I have the Alpha roof system. I did some recalking with Alpha roof calk. I did not use Dicor, I used the Alpha brand. That was the first suggestion.
The second suggestion was Spic-n-span for washing the roof, or any RV rubber roof cleaner, or even Dawn Dishwashing liquid.
But he said to condition the roof with RV Rubber Roof Conditioner. I was really surprised to hear this since the roof was the Alpha system. I'd been using RV Rubber Roof Conditioner on all my prior travel trailers. I followed his advise and I've washed the roof and conditioned it every year in the Spring ever since.
I found the easiest way to apply the Rubber Roof Conditioner is to pour a small amount on the roof and then spread it with a squeegee. You can do it with a sponge mop, but you loose a lot that way, and it leave a heavy thick layer on the roof which is not necessary. The squeegee will spreads the Conditioner very, very thin, filling in the fine pours in the rubber membrane and make it smooth and soft and SLICK as a new born baby butt!
More you do not need to do.
Just beware, if you use any kind of soap on the roof, it will wash over the sides of the camper and streak the sides. So, after doing the roof, you really do need to get around and spray down and even soft brush the sides of the camper too. Otherwise, you'll have streaks on the side. Dawn will remove any wax. Spick n span will glow under a black light (really)!
About the calking, if you have the Alpha system, then get the Alpha calking brand. If you anything else, Dicor is what you want. Nothing else.
Also, I've resealed only a couple very, very tiny spots on my roof caulking only 1 time in 5 years now. I get on the roof every time I pull the slides in to brush off the slides (every time, regardless of where or how long we've been parked), and every time I walk carefully and really look at the calking, inspecting for cracks. I look as if it's the very first time I'm inspecting. ... every time.
I do 2 treatments with the RV Rubber Roof Conditioner. The first will use considerably more. The second treatment (wait 24 hours) will use about 1/4 of the amount you used on the first treatment. When I do mine, I can now expect to use a gallon and and 1/4 (using a squeegee) for the 2 back-to-back treatments. My Montana is 41 feet long with 4 slides. I originally purchased 2 gallons. (actually I had some left over from my previous campers). And then I purchase 1 new gallon every year. What I don't use up this year, I'll use it next year first. I keep it stored in my heated garage, not the cold garage and it's perfectly OK the next year to use. If it freezes, I'd not use it.
So, if Alpha, use Alpha Calking, any cleaner, and Rubber Roof Conditioner:
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