Hello, I have an RV that I currently live in. I took it in for repairs and had a new roof coating put on but they did not do the slide out. It took over a month to get my trailer back so I would prefer to do it myself. The slide out has the rubber trim to keep the rain out of the trailer and so a small portion of the slide out roof is under the trim. How do I coat the roof of the slide out and still maintain its integrity?