We value the roof over our head, but typically we do not have much interaction with our roof and its shingles. Just like everything else in your house you will have to replace it at some point. Whether you have Corning shingles, Home Depot asphalt shingles, something from GAF Materials Corp, or any other shingled roof you will have to take some time annually to examine for wear and other issues. If your roof permits it, climb up there and walk around to examine it. Make sure to look at the best shingles and those that show the most wear. Are they brittle? For example, you should not be able to bend the edge and have it snap off. You want your corning shingles, or the equivalent, to have some resiliency when they bend. That simple test is a good factor in determining how much life is left in them. As an example, the Owen corning shingles typically have a decent warranty against degradation that affects how brittle they become over time. In terms of warranty lengths and how it may apply to your roof you can wiki shingles to gauge if you have warranty coverage left. If not, you will want to adjust your schedule to examine the roof more frequently. You can use binoculars to look at individual corning shingles and their equivalent without climbing up on the roof, especially during the winter months when a chance of falling might be greater. All shingles, Corning shingles or otherwise, have different wind, heat, and other resistance properties. This may also determine how often you might have to replace Owens corning roofing shingles in different areas of the country. If determined that you are looking at replacing Corning shingles or their equivalent, make sure your roofer can follow manufacturing guidelines. They may need to use specific types of nails in specific locations to maintain adherence to warranty specifications. In the long run, this could payoff since your warranty may outlast your stay in your home. If you sell the house, it could be that the Corning shingles, or equivalent, warranty is transferable to the new owners.