What is one expected result of allowing settlement in a drainage installation?

Allowing settlement in a drainage installation can lead to misalignment of the joints. Settlement occurs when soil or underlying material shifts or compresses over time, which can change the position of the pipes or connections in the drainage system. As the pipes settle unevenly, the joints that connect different sections of the piping may be pulled apart or pushed closer together, leading to improper seals and potential leaks.

Misaligned joints can adversely affect the overall functionality of the drainage system, as they may create blockages or hinder water flow, ultimately reducing the system's effectiveness. Maintaining proper alignment is crucial for ensuring reliable drainage and preventing issues that could arise from misaligned connections.

In contrast, the other options do not align with the expected outcome of settlement in drainage installations. For instance, while one might expect drainage efficiency to remain constant, it can actually decrease due to the misalignment. Additionally, temperature regulation is typically not affected by settlement, and the structural integrity of the system may be compromised rather than strengthened.