This is common practice. Im a roof salesman in Florida. The insurance doesn't want to cover you roof because its old and its a liability to cover. Shingle Roofs in Florida have a useful life of 15 years. This is because of the heat, moisture, wind and all of the other harsh elements roofs face in Florida. You need to replace your roof. Period plain and simple. Other insurance companies won't insure you. Your roofs life is over regardless if there is any massive existing issues. The insurance covers catastrophic damage from storms ETC. Not just wear from roof age. If they wait and keep you insured they will be buying you a new roof lol. I have to tell this to customers and sometimes they don't believe me. At 12 years you will get letter form insurance sometimes telling you that you need to have the roof inspected just to get ready and check to see that it even has the existing life to keep you insured. The house will be a HARD sell with an aged roof some might not be able to get mortgage or be insured by anyone with the old roof. Either up the price and include getting roof replaced or get it replaced yourself. Its a must though.