Per the UPC what is the minimum required slope per foot for all horizontal drainage piping?

B) 1/8 inch

C) 1/4 inch

D) 1/2 inch
E) None of the above

Answer: C) ¼ Inch

(Note : There is an exception for pipes 4 inches and larger, but it has to be approved)

708.0 Grade of Horizontal Drainage Piping.

708.1 General. Horizontal drainage piping shall be run in practical alignment and a uniform slope of not less than 1/4 inch per foot (20.8 mm/m) or 2 percent toward the point of disposal provided that, where it is impractical due to the depth of the street sewer, to the structural features, or to the arrangement of a building or structure to obtain a slope of 1/4 inch per foot (20.8 mm/m) or 2 percent, such pipe or piping 4 inches (100 mm) or larger in diameter shall be permitted to have a slope of not less than 1/8 inch per foot (10.4 mm/m) or 1 percent, where first approved by the Authority Having Jurisdiction.