Uh oh, that's not good. It's never a good sign if your roof is looking. Sounds to me like you should probably get it replaced before the damage gets worse. I would recommend hiring a roofing company to do it. Don't try it yourself; chances are you'll make it worse. Hiring a professional will ensure that everything is done correctly. Good luck! http://www.whalleysfourseasonsroofing.ca/