防水

1. Origins, structure, and basic meaning

• Structure: 防水 is read ぼうすい and is a noun for treatment or a property that prevents water from penetrating.
• Basic usage: Express the treatment with 防水加工を施す and an item's property with この袋は防水だ.

2. Common pitfalls and similar expressions

• Treatment and property
  • 防水加工 is a waterproofing treatment, while 防水だ states that an item has a waterproof property. Keep the process distinct from the resulting condition.
• Degree of protection
  • 防水 alone does not guarantee that water can never enter at every depth, duration, or pressure. A product's specific description determines the performance range.
• 防水 and 撥水
  • 撥水(はっすい) focuses on causing water to bead and roll off a surface. 防水 focuses on preventing water from passing through into the interior.