A new tent's waterproofing should last for a few years, especially if it's a good one. Practically all tents come with a good-quality waterproof coating on them from the factory. The amount you'll need to re-waterproof your tent depends on a few variables. The amount of camping, type of camping, and camping climate all contribute to how often you need to waterproof your tent. Even if you're a light, fair-weather camper, it's still a good idea to waterproof your tent every two to three years. A good rule of thumb is to waterproof your tent once a year, no matter how much you camp. A regular overhaul will make your tent last a lot longer. Inspect your tent before going camping. Try to do it a couple of days before you leave. Then, if you do notice any signs of failure, you'll have time to waterproof your tent and let it dry completely.