Ahhh... the wonder of the roof... protecting mankind from the elements since primitive times. Of course, in modern times, the most popular roofing materials are asphalt based rather than twig based, but the concept is the same: to keep us dry and warm.
Does your roof need attention? I recommend annual inspections to uncover potential long-term problems. Have an experienced roofer check the flashing for rust or corrosion (this is the part of the roof that comes together in seams with chimneys and air vents). In the attic, you should check for any signs of water leakage. Pay special attention to areas around drain spouts. Left unchecked, minor roof problems can lead to major structural damage.
If you do have damage to the roof, you'll need to decide whether to remove the roof completely and redo, or to lay over. Lay overs are less expensive, but you'll want to check with your roofer to see what is recommended for your situation. When choosing a roofing contractor, get at least three bids. Ask each of the bidders to submit materials recommendations on the bids as well. This will allow you to compare and contrast the types of materials being proposed by each contractor.
Finally, be sure to inquire about the manufacturer's warranty. For more information, please give me a call.