True or False: A 3-inch horizontal branch drain may accommodate two water closets.

True or False: A 3-inch horizontal branch drain may accommodate two water closets.

• A. True
• B. False
• C. Not specified
• D. Not applicable

Answer: (A)

The main idea here is how horizontal branch drains are sized for the fixtures they carry. A 3-inch horizontal branch drain has enough capacity to serve two water closets, provided the run is properly vented and sloped. In practice, toilets contribute a load that is within the limit of a 3-inch branch, so adding a second toilet on that same branch is acceptable. If you tried to put a third toilet on the same 3-inch branch, you would likely exceed its capacity and risk drainage problems, siphoning, or poor drainage. So the statement is true because the 3-inch branch is designed to handle two toilets when the system is correctly vented and installed.

The main idea here is how horizontal branch drains are sized for the fixtures they carry. A 3-inch horizontal branch drain has enough capacity to serve two water closets, provided the run is properly vented and sloped. In practice, toilets contribute a load that is within the limit of a 3-inch branch, so adding a second toilet on that same branch is acceptable. If you tried to put a third toilet on the same 3-inch branch, you would likely exceed its capacity and risk drainage problems, siphoning, or poor drainage. So the statement is true because the 3-inch branch is designed to handle two toilets when the system is correctly vented and installed.