According to code, what is the minimum size of a trap for three lavatories connected to one trap?

The minimum size of a trap for three lavatories connected to one trap is correctly identified as 2 inches. This is established by plumbing codes that provide guidelines on the proper sizing of traps to ensure adequate drainage and prevent clogs.

When multiple fixtures, such as lavatories, are connected to a single trap, the diameter of the trap must be sufficiently sized to handle the combined flow from all the fixtures. A 2-inch trap is designed to accommodate the capacity required for three lavatories, taking into account the potential for increased wastewater volume.

In practical terms, sizing the trap appropriately helps maintain sufficient flow rates and prevents slow drainage or backup issues. It's important for plumbing systems to adhere to these standards to ensure long-term functionality and hygiene.