Codes

Question 1

Required slope for different sized sewer pipes

Answer 1

1/4” : 12” (2%) for 2” pipes

1/8” : 12” (1%) for 3-6” pipes

Question 2

Required slope for site drainage away from building

Answer 2

5% min away from buildings

2% min for impervious surfaces

1.5% - 10% for grass areas

Question 3

Required slope for paved parking lots

Answer 3

2% - 3%

Question 4

Slopes for ramps (ADA vs IBC)

Answer 4

ADA Ramps

Not greater than 1:12 (8.33%)

See 2010 ADA Section 405

IBC Ramps
Not greater than 1:12 (8.33%) when it’s a component
 in a means of egress

Not greater than 1:8 (12.5%) elsewhere

Question 5

Slope at turning radius per ADA

Answer 5

1:48 max (2%)