Obviously, the older your shingles are the sooner they will need to be replaced. If your roofing is less than 20 years old, then you are probably okay. However, improper ventilation can make the material wear out quicker. In addition, it does matter whether or not you have multiple layers attached to your roof. Chances are if the material is coming up on 20 years old and has a layer or two underneath, then you probably need to replace it.
There are valleys on every housetop. This is the way snow and rainfall travel down and into the gutters. However, if the shingles around the valleys are starting to fall apart, then it is time for a replacement.
Buckling and Curling
If you see shingles that look as though they are curling up then it is a sign you need to replace them soon. Buckling on the surface is also another indicator. The best way to tell if it is just a single shingle or the entire surface is to check the ones in direct sunlight. If these are showing any signs of curling or buckling, you should contact a licensed roofing company to make repairs. If the roof is relatively new, it can indicate a defect in the material.
If you notice that tiles are missing, it could indicate that the materials need to be replaced. Frequently, this occurs after the house is hit by a storm. While you may think it would be easier to replace the missing items, there could have been more damage to the housetop than you realize. Before you go nailing new tiles in place, have a licensed professional check the area to make sure no other damage has occurred.
As your tiles age, they begin to lose the granules from their surface. Those who have gutters installed on their homes may see these particles accumulate in the guttering. This is a sign that the fiberglass covering is wearing out. However, you do not have to have an accumulation of granules to see this effect. If you are looking at the shingles and see a color that is not the original color of the surface or you are starting to see white coming through, that is the fiberglass underneath and it is time to replace your roofing.
Probably the most obvious way to tell that you need to have the surface of your housetop replaced is by discovering leaks. If water drips through the ceiling on a rainy day, you have waited too long to have the necessary repairs. Now there is damage to the plywood underneath the surface. Of course, you can still have this damage without having any leaks. If you are in your attic looking up and see daylight, you need to replace your roof.
Learning these signs will ensure that your home stays out of the elements.