What is a common mistake during the installation of drainage pipes?

Ensuring proper slope and alignment is critical when installing drainage pipes because it directly impacts the effectiveness of the drainage system. A proper slope helps facilitate the flow of water by using gravity, which is essential for preventing water build-up or stagnation within the pipes. If the slope is inadequate, water may not flow efficiently, leading to clogs or backups. Additionally, misalignment can create stress on the piping system, potentially causing leaks or failures over time.

Other factors, while they may seem relevant, do not directly contribute to the core functionality of the drainage system as significantly as slope and alignment. For instance, using too many pipes can lead to unnecessary complexity or increased costs, but it doesn't inherently affect drainage if installed correctly. Similarly, installing pipes above ground or choosing decorative materials might have visual or structural implications, yet they are not fundamental to the drainage system's operational integrity like correct slope and alignment are. Therefore, this choice highlights a vital aspect of effective drainage installation that must be adhered to in order to achieve optimal performance.