Drainage, Waste & VentQuestion 28 of 120
A horizontal fixture branch serves three lavatories only. Any branch that receives the discharge of a water closet must be at least what size?
a.1-1/2 in
b.2 in
c.2-1/2 in
d.3 in
Explanation
No drain receiving the discharge of a water closet may be smaller than 3 in, regardless of how few fixture units are on it. The 1-1/2 in and 2 in sizes serve lavatories, sinks, and similar small fixtures, and 2-1/2 in is not a size used for water closet drainage.
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