Typical Household Drainpipes:

  1. Toilet drains
    • Toilet drains will typically measure roughly 3 inches in diameter
  2. Sink drains
    • Sink drains are typically 1 ½ inches to 2 inches in diameter
  3. Bathtub and shower drains:
    • These drains will typically measure 2 inches in diameter
  4. Primary collection drains
    • May vary between 3-4 inches in diameter

Once flushed, sewer drains are relatively empty containing predominantly air and sewer gas.