Concealed works such as water circuit renovation will directly affect future life use, so we should guard against death in the process of renovation. After years of use, the original decoration of the old house will be outdated, so there may be water leakage. After re-waterproofing, it is necessary to conduct a 24-hour water avoidance test to verify whether the waterproof layer is intact. Generally speaking, the waterproof layer of shower room is 1.8m, the height of other wall waterproof layers is 1m, and the waterproof layer on the ground is 30cm higher. If there is no waterway reconstruction during the decoration, it is also necessary to check whether the waterproof layer is intact. Punching and slotting in the decoration process may damage the waterproof layer. Therefore, if the tiles are removed from the decoration of second-hand houses, they should be re-tested to ensure that there is no problem with the original waterproofing. After the circuit transformation, it is necessary to check whether the sockets and switches can be used normally and whether the installation position meets the original requirements. Bathroom drainage should not be changed to some old-fashioned bathrooms for side drainage at will. The floor height of such bathrooms is much higher than that of living rooms and bedrooms. Once changed, it will affect the floor structure of the bathroom and even cause inconvenience to the residents downstairs, so this drainage method cannot be changed at will. At the same time, if the squat sanitary ware is changed into a toilet, it needs to be waterproof again. It is inevitable to knock on the wall and the ground in the renovation of old brick-concrete houses, but some old brick-concrete houses need to be demolished and rebuilt with caution. The wall of brick-concrete structure plays the role of bearing and earthquake resistance first, and then plays the role of enclosure and separation. If the load-bearing wall is destroyed only to realize the idealized spatial pattern, the load-bearing and seismic capacity of the wall will be weakened, resulting in potential safety hazards. Therefore, when demolishing, renovating and renovating, we must take into account the building structure and safety issues, and make bold innovations on this basis, otherwise, once the project is started, it will cause irreparable losses. Some old houses on the top floor have heating pipes, which affect the indoor beauty. The simplest way is to wrap these pipes around the roof as a ceiling. It should be noted that the circulation and flow rate of these heating pipes are often better than that of radiators, so they will make the room warmer in winter. When winding the heating pipe, enough cooling holes should be left, which can not only let the hot air flow out, but also avoid the gypsum board ceiling from cracking and deformation due to long-term baking by the hot air.