Venting an island sink (if below-floor trap not permitted)

Plumbing · Venting Systems · printed page 292 (PDF page 293)

Book index entries

Island Sink – Venting (Below-Floor Trap Not Permitted)Venting – Plumbing – an Island Sink – Below-Floor Trap Not Permitted Plumbing

Text in the illustration

fixture outlet pipe (tail piece)
vent
island sink
if the code-allowable tail piece length does not permit the trap to be located below the floor, a loop or circuit vent arrangement will have to be provided
wall
cleanout
foot vent
floor framing
drain

Generated explanation

The illustration shows an island sink with its trap above the floor, connected to a vertical drain that extends below the floor framing. A loop vent rises within the island cabinet, bends over near the underside of the countertop, and returns downward through the floor. Below the floor, the returning vent connects to the drain and to a foot vent running toward a vertical vent in a nearby wall. Cleanouts are shown at the below-floor drain connection and at the wall vent. The annotation specifies a loop or circuit vent arrangement when the code-allowable tailpiece length does not permit a below-floor trap.

Components

island sink faucet sink cabinet countertop fixture outlet pipe (tailpiece)sink trap vertical drain loop vent foot vent wall vent cleanouts drain piping floor framing wall

Materials

wood framing

Related illustrations

1640

Venting an island sink (below-floor trap permitted)

· p. 290

The illustration shows an island sink with a long vertical tailpiece extending through the floor to a trap accessible from below. The trap outlet connects to a horizontal drain beneath the floor. A vent branch rises from

1641

Loop vent or circuit vent for an island sink

· p. 290

The illustration shows an island sink with a tailpiece and P-trap located above the floor inside the cabinet. A loop vent rises beside the sink to just below the countertop, then returns downward through the floor to the