Yes. That is why it's recommended to use instead of gypsum drywall in wet applications such as bathrooms/showers, etc.
concrete
yes
If it sits over a cement floor, then no. If it is a nailed down floor, then you can, but you still have to install a cement board.
tawad Board
You COULD, but there's no real need to.
Waterproof cement is cement that is waterproof. It can be applied to a surface without being affected if it was touched by water.
concrete
Thhis cement is impregnated with sodium or aluminium stearate.
Cementuous materials are not waterproof. Hydraulic cement is the closest they come, but even it becomes saturated.
Cement board, at most contractor supply places it will be called DUROCK cement board or Permabase cement board. = =
To form a waterproof barrier.
If you are inhaling cement board, you need a qualified safety professional or industrial hygienist to show you how to do the work without inhaling cement board.
A cement board can be used on the exterior of buildings . Cement boards are also convenient when making patios and decks as an extension in modern homes
it is waterproof
Older cement board may contain asbestos, and then it is properly called "asbestos cement board." Cement board more recently manufactured should not contain asbestos. The only way to know whether a particular cement board does or does not contain asbestos is to ask the manufacturer (if you know who made it) or have a sample collected from it by a qualified sampling technician and have the sample analyzed by a qualified laboratory.
yes
yup but if your using it on electrical or papery things coat the thing entirely