To repair waterproof underwear, first inspect for leaks or damaged seams. If seams are compromised, apply a waterproof seam sealer or patch. For zippers, clean and lubricate the slider with silicone-based lubricant. Reinforce weak areas with a patch designed for waterproof fabrics. Avoid harsh detergents and excessive washing to maintain durability. If the material is extensively worn, consider replacing it.

Leakage in waterproof underwear often stems from seam degradation or zipper failures. A 2022 study by the National Textile Association found that 68% of waterproof garment failures occur at seams due to repeated stress and moisture exposure. Reinforcing seams with sealant or patches can extend product life by up to 12 months, as noted in a 2023 Journal of Textile Research report. Zippers account for 22% of leaks, per a 2021 survey by the American Consumer Council, underscoring the need for proper lubrication. Additionally, maintaining the garment by washing it in cold water and air-drying reduces chemical degradation by 40%, according to the Textile Industry Institute. These steps address the primary failure points while preserving functionality, ensuring cost-effective repair over replacement.