EVA itself has excellent waterproof properties, and its molecular structure is tight and not easily penetrated by water. This material forms a continuous waterproof barrier during the manufacturing process, which can effectively block the entry of water. Therefore, even after repeated use, the basic waterproof ability of the matte waterproof reusable adult EVA raincoat usually does not decrease significantly. Only when the material is physically damaged, such as scratches, tears or seams, will local water seepage problems occur.

Although the EVA material itself has strong waterproof properties, long-term use may still cause partial weakening of the waterproof performance. Frequent folding, friction or long-term contact with other items may cause slight wear of the matte coating or EVA film on the outer layer of the matte waterproof reusable adult EVA raincoat. Although this wear will not completely destroy the waterproof function, it may affect the effect of water droplets sliding off the surface, making the raincoat look "not so waterproof anymore".

In daily use, the raincoat may be stained with dust, sweat or oil. These impurities may clog the micropores on the surface of the raincoat. Although EVA itself does not absorb water, dirt will affect the "lotus effect" of water droplets, causing the water droplets to no longer roll off quickly but to adhere to the surface. Machine washing, strong rubbing or using irritating detergents may damage the structure or surface treatment layer of the EVA film, thereby reducing the waterproof performance. High-temperature drying may also cause the material to deform or age. Long-term exposure to sunlight may gradually harden and brittle the EVA material, affecting its flexibility and waterproof durability. However, regular EVA raincoats usually add anti-UV agents to delay this process.

In order to ensure the long-term stability of the waterproof performance of the raincoat, it is recommended to rinse with clean water or gently wash by hand with a neutral detergent after use, and avoid using a hard brush or strong scrubbing. Dry naturally after washing, avoid exposure to the sun or high-temperature drying. When storing, the raincoat should be stored in a cool and dry place, avoid long-term exposure to sunlight or near heat sources to prevent accelerated aging of the material. Before use, check the seams and coating of the raincoat to see if they are intact. If local water seepage or wear is found, use waterproof repair spray to repair it. If the seams are debonded, use waterproof tape to reinforce them. When folding and storing, avoid squeezing with sharp objects to avoid scratching the EVA film. If the raincoat is equipped with a storage bag, it is recommended to store it in the storage bag to reduce unnecessary friction and folding damage.