If you decide to hire their own crew or tiler to repair the bathroom.
Then you need to consider the following points:
1. At the first meeting. Do not believe the stories that will do everything super, etc. If you think that define professionalism in appearance it is also a mistake. Just checking empirically, will tell who is who. By experience we say that 80% is a super masters laborers with high self-esteem. In winter, their number is significantly increased.
2. If you have curves of the walls (even in panel houses reach 40-50 mm deflection of the vertical). The evenness of the wall is not determined by eye, and instrumentation. In no case can align wall tile adhesive (thickness of tile adhesive layer is regulated by the manufacturer and is not more than 10 mm. Walls should be aligned with a mixture of plaster!
3. Enclose at least a model contract prescribe in detail all work on paper with the prices and units (m2, rm, NY) immediately arrange a fixed price, say that if you suddenly emerge unforeseen work, you do not pay for them will. Some unscrupulous gang announce deliberately undervalued jobs. And in the future they emerge suddenly extra work. So make sure that all the work would have been counted once. Otherwise, the budget team can be paid.
Prescribe in the warranty contract, according to the Law on consumer protection, it should be a minimum period of 3 years.