Most residential plumbing and electrical installations are carried out by professionals; however, it is still important to acquire some basic knowledge on your own. Without such knowledge, you will have no way of assessing the quality of the work or determining whether the design is sound, and you will also be unable to communicate effectively with the contractors during the construction process. Before starting any plumbing or electrical work, it is essential to obtain the construction drawings—both the electrical design plans and the comprehensive drainage design drawings. These documents will enable you to evaluate the reasonableness of the plumbing and electrical designs and identify the specific locations where certain switches and valves should be installed.

During electrical and plumbing installation, it is crucial to avoid leaving wires exposed, especially when conductors are directly embedded in walls, under floors, or on ceilings without any protective covering. Over time, such exposure can lead to external corrosion, increasing the risk of short circuits and reducing the service life of the wiring. The correct installation procedure is to first install conduits and then run the wiring through them; the conductors should be routed inside PVC conduit to provide adequate protection.

During electrical and plumbing installation, conduit sizes and types vary to accommodate circuits with different voltages, separate circuits, and signal lines; under normal circumstances, conductors of different types should not be routed in the same conduit. In addition, lighting fixture installation should be carried out after interior finishing is complete—specifically, once all wall surfaces have been finished—to prevent paint or other materials from contaminating the fixtures during painting. The bolts securing each fixture must be firmly tightened, with at least two bolts per fixture, and fixtures must never be mounted on combustible building components.

During electrical and plumbing installation, the installation of light switches and electrical equipment switches is a critically important step. These switches must be connected to the phase conductor; if they are installed on other circuit conductors, the switch and the associated electrical equipment will remain energized even when the switch is turned off, which can easily lead to electric shock and poses significant safety risks. When installing wiring, all splices must be securely fastened, and splices must never be run through conduit. Otherwise, if a splice fails or breaks in the middle of the line, it will be impossible to repair, thereby compromising the normal operation of the circuit.

During plumbing and electrical installation, joints are indispensable; however, it is crucial to ensure that the smooth connection points of wiring and piping are securely fastened to prevent loosening during use. When installing plumbing, a thorough inspection of all pipes is essential. In particular, when installing drainage pipes, attention must be paid to their routing: each pipe should have an appropriate slope, and all joints must be tightly sealed to eliminate any gaps or leaks. Additionally, the pipes should be firmly supported on brackets to ensure stability. These are fundamental principles of plumbing and electrical installation; only by understanding them can one know what to focus on during the installation process, communicate effectively with the construction team, guarantee construction quality, and promptly identify and address any issues that arise on site.