Backpacking sleeping pads can last for years, or even decades, depending on how you care for them—most top manufacturers offer limited lifetime warranties as a result. The most important step is to always take care to ensure that there are no sharp objects on the ground below your backpacking sleeping pad when setting up for the night. (Although if you do end up with a hole in the pad, they are easy enough to repair it, as long as it isn't along one of the seams.) At home, give your backpacking sleeping pad some time to air dry after each trip before storing it away for the season to help reduce the potential of mold accumulation.