If your ceiling is showing brown spots, you certainly need to get your roof reshingled. We've had the same issue for the last couple of years, so this April I had a crew come in and re-shingle our place. The original roof had the shingles installed over a tar paper underlayment, and this tar paper was breaking down, and some of the shingles never really sealed to each other fully....so every time we had a heavy rain, with strong winds, we'd get "spots" on the ceiling. I had the roof completely stripped, synthetic underlayment installed, and Owens Corning architectural shingles put down with 6 nails. This gives us a roof that is warranteed for 30 years and should withstand winds of 130MPH.