Common Signs of Deterioration :
The condition of a roof's shingles can be tested against a number of factors. Are your shingles cracked, torn, faded, curling or blistering? Are the nails holding them on loose or coming out? Is the flashing around your chimneys, vent pipes or wall junctions letting in water? Are there gaps or cracks in caulked areas? Are there holes in the valleys? If so, it may be time to get a new roof, especially if the one you have now has served you for a long time.