If you buy a second-hand house, you need to remove the previous tiles and ceiling. When removing the tiles, pay attention to removing the cement cushion together. Do not only remove the tiles in order to save money, or your floor will be much higher. When removing the floor tiles with floor heating, we must pay attention to the protection of the floor heating pipes to prevent them from being broken. When the floor tiles of the toilet and kitchen are removed, the water outlet must be sealed to prevent the sewer from being blocked by garbage. For the demolition of the walls of the new house. In fact, I am not particularly in favor of the removal of the room wall, because the bearing wall, counterweight wall and top beam are not movable, and even the removal of non bearing wall will affect the seismic resistance of the whole building (personal removal is not too big a problem, but if the whole building residents are free to remove unless the bearing wall, it will greatly reduce the seismic resistance of the building). If it is necessary to demolish the wall, it is better to get the design drawing of the room, so that it can distinguish which walls can be demolished (this is to find the property). If we can't get the drawings, we need to distinguish the bearing wall and non bearing wall artificially. First of all, let's know what are the load-bearing walls. The walls under the girders of the frame structure are non load-bearing walls. The long direction of the external walls and bays of the brick concrete structure is generally load-bearing walls, which is absolutely immovable. What can't move is the counterweight wall, which means there will be a door and a window between the balcony and the room. The window can be removed, but the wall can't move. Then there are the top beam and the steel bar. Toilet and kitchen also try not to move, if you move must do a waterproof, and do closed water test. If there is no special requirement, light materials shall be used as far as possible.