How to Install a Floor Drain Standpipe

How to Install a Floor Drain Standpipe.
Standpipes provide homeowners with an alternative way to manage messy and often expensive back flows and flooding situations by adding an additional length of piping (the standpipe) to existing floor drain pipes via a standpipe flood guard gasket. Follow these steps to quickly install floor drain standpipes.

Step 1

Choose a standpipe flood guard gasket model by following our link in the Resources section. Buy a 1 1/2-inch IPS pipe if using a 4-inch standpipe flood guard gasket.

Step 2

Remove your floor drain trap and clean both the trap and your floor drainpipe.

Step 3

Install your standpipe flood guard, if installing the 4-inch model, by placing the guard into the top of the pipe below the floor drain trap inset area with the screw heads facing up.

Step 4

Turn the screws with your flat or cross head screwdriver until the rubber gasket seals tightly against the drain pipe and then thread your 1 1/2-inch IPS pipe into the gasket. If using the 3-inch model, thread your pipe into the flood guard gasket before placing the gasket into the pipe.

Step 5

Push or screw your floor drain trap back into the floor drain. If you have difficulty with reinstalling the trap, lightly tap the trap back into place with your rubber mallet.

Things You Will Need

  • Flood guard
  • Standpipe
  • Screwdriver
  • Mallet


  • Always check the standpipe where it connects to the flood guard gasket as improperly threaded or cross-threaded pipes can leak at the connection point.
  • Never install a standpipe in a high foot traffic area as the pipe sticking out of the floor can pose a fall hazard.
  • Standpipes can alleviate back flow pressure and reduce the chances of building or pipe damage from pressure, but they do not stop high pressure back flows. Always keep in mind that high pressure back flows can overflow standpipes or cause improperly installed standpipes to "blow" out of floor drains.