Can you make clothing that is no longer waterproof 100% water-resistant again by waterproofing it? Clothing that is no longer waterproof cannot be made 100% so again, even with waterproofing. Related articles When do I use waterproofing spray (e.s. Waterproofing spray for textiles) and when do I use wash-waterproofing? What do I need for correct shoe care? Which detergent is suitable for caring for functional clothing? How long does basic waterproofing last and how often should I waterproof? Do you need special detergent to wash a functional jacket?