Is the shower room floor flat?

The advantage of the condition is that the drainage is more comfortable, and the foot will not slip because of a lot of water; >>>More

Yes, you must use antique surface, otherwise it will be very slippery, and you must do a good job of protective treatment, otherwise there will be alkali return, yellowing, mildew and other lesions in the later stage.

Yes, but take waterproof measures.

One of the ways to do this is if you install a circulating pump, so that when you turn on the shower, the water will be pumped into the drain, and you'll be almost done with the shower.

The groove is inconvenient to clean and hygienic ......So it is better to level the non-slip. >>>More