Sliding doors are a common type of door in most homes and workplaces. They are made with a simple piece of metal that slides up and down on a track. However, sliding doors have a limited lifespan, so it is important to replace them at the right time. There is no single answer to this question because different sliding door models have different lifespans. For example, if you have an older model that was made before 1980, it should be replaced every 10 years. If you have a newer model that was made after 1980, it should be replaced every 15 years. The best way to find out how often your sliding door needs to be replaced is by asking your manufacturer or installer for more information about the specific model you own.