Do you know how much it could cost you to replace your roof? On average, the price ranges between 1 and 9 dollars per square foot, which can add up to quite a bit of money. If your roof were to fail you, you can expect damage from rain and snow, as well as, an ever increasing heating and cooling bill.
The worst thing for your roof is standing water. When water stands still on a roof, it encourages mold and moss growth. Depending on the material, it could also cause it to rust or rot. To prevent this from happening, you need to keep your roof clean and your gutters working.
If you have nailheads protruding on your roof, this likely means that the wood they were attached to has begun to deteriorate. You will need to remedy this problem, but it will probably require you to get help from a professional.