Drain and Vent

Drain and Vent / Kitchen sink

Double bowl kitchen sink with disposal, in an island, AAV

The sink is in an island with no wall behind it, vented by an air admittance valve under the sink. Two bowls joined by a continuous waste. A disposal on the sink.

Where the sink is
Bowls
Disposal
Dishwasher

Get this room's rough-in sheet, $7

Kitchen sink
Your room as a display drawing. The pipe sizes, the vents, the falls and every rough-in height are on the sheet.

What is on your rough-in sheet

Three Letter pages for this room (kitchen sink), drawn for your sink wall. Print them and tape them to a stud.

  1. Sheet 1

    The riser drawing

    Every drain and vent pipe drawn at its size, the vents dashed, the fall marked on every run, and where each fixture ties in.

  2. Sheet 2

    Plan and wall

    The floor plan with every drain located from the walls, and the plumbing wall with every stub-out, valve and shower head height.

  3. Sheet 3

    The counter list and the checks

    Every fitting by name and size, counted, to read out at the supply house. Each trap arm checked against its limit, and the test the inspector will ask for.

Checked before it is drawn

  • Every branch sized for the fixture units it carries (IRC Table P3005.4.1)
  • Every trap within its distance to a vent (Table P3105.1)
  • Wet vents sized and ordered as P3108 requires
  • Every fixture vented; AAVs placed as P3114 requires
  • Falls of 1/4 or 1/8 in per foot by pipe size (P3005.3)

Before you cut

  1. Pull the permit. Most places need one for new drains and vents, and the inspector sees the rough-in before the walls close.
  2. Find your code. This sheet follows the IRC. Many western states use the UPC, and some cities ban AAVs. A call to the building department settles it.
  3. Shut the water off before you cut into a supply line, and open a faucet below to drain it.
  4. Check the joists. On a wood floor, a drain across the joists means bored holes, and holes have size limits.

For this room

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