Nothing in this world lasts forever, and your roof is no exception to this rule. Most homes come with asphalt shingles that need to be replaced every 20-30 years, but the actual date will depend on several factors including the quality of the shingles, the weather, and maintenance schedule. Rather than setting an arbitrary date to do the replacement, look for these signs that your roof is going to need replacement in the near future.
You Are Starting to Get Leaks
Usually a leak in your roof means you only need to repair the area, but not always. The easiest one to diagnose is when your roof suffers major damage after a storm. Even severe weather rarely does more than pull off a few shingles, but occasionally, branches or other flying debris will put a serious hole in your roof. At the very least, this will mean replacing a large section of the roof and underlayment.
With a more traditional leak, it can be more difficult to determine whether repair or replacement is in order. The big question will be whether you can fix the leak by replacing a few shingles, or if the water has damaged lower layers of the roof. If so, then replacing the whole roof is the only way to ensure that the wood beneath does not continue to rot. You might be able to get a sense of the situation by inspecting the area around the leak in your attic, but it is best to get a final determination from a professional before committing to a while roof replacement.
The Shingles Are Starting to Break Down
You might manage to avoid a leak, but you can't avoid the ravages of time. Over the years, the materials that hold the shingles together will start to come apart. While you are cleaning your gutters in the fall, take a look at what is ending up in the gutter. Leaves and sticks are pretty normal, but when the shingles start to break down you will start to find the granules that cover the surface of the shingles in your gutters.
While you are up there, take a look at the condition of the shingles. If your shingles are ready to fall apart, the shingles will actually start to shrink and the edges will start to curl. By the time they are ready to go, these changes should be easily visible.
You Are Losing Shingles Rapidly
The shingles themselves aren't the only piece to this picture. There are also the nails that hold the shingles on the roof. If they weren't properly tacked down, you can start to lose more shingles than you can afford. Your roof can certainly stand to loose a shingle or two during a major storm-- you just need to replace it as soon as possible. However, if you lose a large number quickly, you might be in trouble the next time it rains. Once you start losing shingles on a regular basis, you should get your roof replaced before you can't keep up anymore.
Even if your shingles are sliding off the roof, the original installation may not to be to blame. As the shingles start to break down, they can easily detach from the nails, and slip off the roof during the next windstorm.
If you aren't sure if it is time or not, have a roofer come out and do an inspection. They will be able to tell you how much longer you can expect your roof to last, as well as if you could make your roof last longer by doing some roof repairs. You should have your roof inspected and maintained at least once a year, so now is the perfect time to start that habit.