Ill. Admin. Code tit. 77, pt. 890, subpt. M, app A, tbl. K

Current through Register Vol. 49, No. 2, January 10, 2025

Table K - Size and Length of Vents

Size of Soil or Waste Stack	Fixture Units Connected	Diameter of Vent Required (Inches)
		11/4	11/2	2	21/2	3	4	5	6	8
		Maximum Length of Vent (Feet)
11/4	2	30
11/2	8	50	150
11/2	10	30	100
2	12	30	75	200
2	20	26	50	150
21/2	42	30	100	300
3	10	30	100	200	600
3	30	60	200	500
3	60	50	60	400
4	100	35	100	260	1,000
4	200	30	90	250	900
4	500	20	70	180	700
5	200	35	80	350	1,000
5	500	30	70	300	900
5	1,100	20	50	200	700
6	350	25	50	200	400	1,300
6	620	15	30	125	300	1,100
6	960	24	100	250	1,000
6	1,900	20	70	200	700
8	600	50	150	500	1,300
8	1,400	40	100	400	1,200
8	2,200	30	80	350	1,100
9	3,600	25	60	250	800
10	1,000	75	125	1,000
10	2,500	50	100	500
10	3,800	30	80	350
10	5,600	25	60	250

Agency Note: Per Section 890.1580(e), no more than 20 percent of the maximum developed length may be installed in the horizontal position. Vent piping serving floor drains shall be installed in such a manner as to minimize horizontal vent distances.