Question: Per the 2015 UPC the minimum size trap and trap arm for a bathtub is _____ inches

A) 1-¼  inches

B) 1-½  inches

C) 2 inches

D) None of the above

Answer:  B) 1-½  inches

Per the 2015 UPC

From Table 702.1

Bathtub or Combination Bathtub/Shower- 1-½ Inches



Table 702.1

Note 7: Trap sizes shall not be increased to the point where the fixture discharge is capable of being inadequate to maintain their self-scouring properties.