1, the outer wall is not waterproof, and nothing the inner wall can do will help;

2. If there is any way, put pressure on the property and complete the maintenance within a time limit; Or ask someone to do exterior wall treatment and property settlement fees.

3. The interior wall should also be waterproof, and try to avoid sitting on some decorative materials such as wood veneer or wallpaper. It is easy to grow mildew when the moisture is heavy.