What does VTR stand for in plumbing terminology?

In plumbing terminology, VTR stands for "Vent through roof." This term is important because it describes a specific type of venting system that is essential for proper drainage and ventilation in a building. The venting system allows gases and odors to escape while ensuring that waste flows smoothly through the plumbing pipes. When the vent extends through the roof, it helps prevent the buildup of harmful sewer gases within the building and protects against possible back pressure that could disrupt waste flow.

The other terms, while they may relate to concepts in plumbing, do not accurately represent what VTR stands for in this context. For instance, "Vertical transfer return" and "Vent through room" are not standard terminologies used in plumbing, and "Vent to roof" is not the conventional phrasing used in the industry. Thus, “Vent through roof” is the correct interpretation of VTR, reflecting a crucial aspect of effective plumbing design and functionality.