Bathroom and toilet officially speaking is a bathroom unit. A space it takes makes only 6-8% of the general flat area, but considering its importance it is out of competition. It is possible to imagine an apartment without any room or even without a kitchen (there is no kitchen as such in “studios”, it is joined with the living room), but it is quite impossible to imagine an apartment without a bathroom unit. Major repairs of a bathroom unit is technically quite a difficult task, it is not a joke. You should leave this work only for highly skilled specialists.
At first, if a quality of mounting and finishing works can be checked by anyone (for example, a wall is curved, a window or a door does not close, or tiles are put roughly), then a quality of plumbing mounting, sewage and electrical systems you can’t check.
And secondly, as a result of bad work your neighbours can be flooded, constantly clogged sewage system, short circuit failure in the electric wiring due to the contact with water and other serious problems.
We have already written a lot about floors, ceilings and walls, therefore I will remind you briefly that all the materials...