Sec. 491(9). Vents.
No brick, sheet metal, earthenware or chimney flues, shall be
used as a sewer ventilator, or to ventilate any trap, drain, soil or
waste pipe.
Vent pipes from closets, sinks, bath tubs, basins, urinals wash,
trays and other fixtures requiring vents, shall be either lead,
cast iron, galvanized wrought iron or galvanized mild steel pipe
with proper fittings. All pipes when not vertical must have a
continuous up-grade to avoid trapping of condensation.
All water closets placed in buildings must be back vented by
2″ pipes, below the floor and as near the flange of closet as possible,
except such as are hereinafter specified. Where there is
only one water closet on the line of soil pipe, no back vent is required
except main soil pipe running through roof, but when
more than one water closet is located on the line of soil pipe, all
other except the top closet shall be vented. No horizontal vent
line longer than 3 feet, permitted beneath floor. In all cases
where closets are located more than 3 feet from main vent they
shall be vented and in cases of battery of closets the inspector
may authorize the omission of the separate vents and the substitution
of an extension of a circuit or continuous vent, not less than
2″ in diameter for two closets and 3″ in diameter for 3 to 6 closets.
Such vents to be taken off at a point between the last two closets
or rising at an angle of not less than 45 degrees from the last
closet.
The vertical vent pipes for water closets in buildings more
than four stories in height, must be at least three inches in diameter
with two inch branches to each water closet bend or trap.
This pipe shall be connected near the base of soil pipe line and
extended separately through the roof, with suitable branches
from each floor connecting therewith.
All vent pipe terminals when within fifteen feet of window or
other opening, must be carried two feet above the highest opening.
Back vents for fixtures shall be not less than as follows:
| 1 Lavatory |
1¼″ |
| 2 Lavatories |
1½″ |
| 3 to 6 Lavatories |
2″ |
| 1 Sink |
1½″ |
| 2 Sinks |
2″ |
| 3 to 6 Sinks |
2½″ |
| 1 Bath Tub |
1½″ |
| 2 to 6 Bath Tubs |
2″ |
| 1 Laundry Tub (1 Trap) |
1½″ |
| 2 to 6 Laundry Tubs (1 Trap) |
2″ |
| 1 Wall Type Urinal |
1½″ |
| 2 to 6 Wall Type Urinals |
2″ |
| 1 Urinal Stall |
2″ |
| 3 Urinal Stalls |
2″ |
| 3 to 6 Urinal Stalls |
3″ |
| 1 Foot Tub |
1½″ |
| 2 to 6 Foot Tubs |
2″ |
| 1 Slop Sink |
2″ |
| 3 Slop Sinks |
2″ |
| 3 to 6 Slop Sinks |
2½″ |
| Shower Stall |
2″ |
Fixtures, other than water closets, connecting into waste pipes
which do not carry waste from closets located above them, need
not be back vented when within four feet of such waste pipe;
this section will apply only to main 4″ soil stack in buildings up
to 4 stories in height and the number of such fixtures shall not
exceed four.
Fixtures located more than 4 feet from main or branch waste
lines are to be back vented except as specified elsewhere.
All openings left in soil, waste or vent pipes for any purpose
and not used in finishing shall be closed so as to be gas and water
tight and in case of vent pipe outlets where they are liable to
hold water, they shall be connected to waste.
