How much larger should sleeves be than the pipes passing through a foundational wall?

The correct answer states that sleeves should be two pipe sizes larger than the pipes passing through a foundational wall. This requirement ensures that there is adequate space around the pipe for multiple reasons.

First, allowing for extra room helps accommodate thermal expansion and contraction of the pipe materials. Pipes can expand or contract when temperatures change, and having a larger sleeve prevents undue stress that could lead to damage or leaks.

Additionally, the increased size aids in the prevention of moisture accumulation. Insulating non-metallic pipes, for instance, can keep condensation from forming, so having a sleeve that is bigger ensures that any potential dripping or water from external sources does not cause a buildup around the pipe.

Moreover, a larger sleeve makes it easier to manage and install the pipe and allows for future modifications or repairs without the need for extensive demolition of the wall. It can also facilitate better drainage should the need arise.

This two-size rule ensures that installations are compliant with industry standards and reduces the risk of problems occurring later on, which is why it is emphasized in plumbing codes.