can share more regarding cementitious? Just apply the cementitious on top of the tiles without removing the tiles? thanks.

you mean cementitious can only be used after removing the existing tiles right?
any recommended method which do not need to remove tiles?

is my toilet floor leak to downstairs. I suspect is the joint between wall and floor.
liquid coating means i can buy some liquid chemical to apply on it?
i plan to apply some thing call PYE KREK-SEAL

Normally how long can it last? Can last 2 years?

I guess if you are staying in apartment condo and having leaking problem from upper unit but the upper unit keep on delay and does not take action, the only solution is to use pu injection.

I think water is the most troublesome issue for a building. Especially for apartment. Electricity or wiring are still ok. But water and piping and water proof is a real problem.