I want to put waterproof wallpaper in my bathroom, do I need to make the wall waterproof? The walls

The bathroom must be waterproof, generally meter high.

1. It is recommended that you do not paste waterproof wallpaper in the bathroom, because no matter how waterproof, after all, it is wallpaper, the bathroom is a humid and humid environment, which is not suitable for wallpaper, even if the waterproof wallpaper will not be too long, and it must be waterproof to stick to the wall, and the wall is of course fine sand gray, otherwise how to flatten the wallpaper.

What material is constantly pasted in the bathroom, it must be waterproof: prevent water seepage to the next room. The rough surface of fine sand gray is sticky.