I have a 27' 8" Nu Wa Hitch Hiker II that I have owned for about a year. It is in fantastic condition. I would like to keep it that way. I thought that I would seal the seams on the roof. The parts store asked me is I had a fiberglass or metal roof. I didn't know. I looked at it and I am still not sure. I think that it may be fiberglass but I am not positive. I have two questions. First, does anyone know what material the roof is made of? Second, The seams appear to have a tar like substance on them. Should it be there? If not, shoud I scrape it of and if I do, what should I replace it with? Thank you.