Kitchen Island Drain Vent

One solution is to install a vent that loops under the floor.

Kitchen island drain vent.

So it won t plug up the vent must rise six inches above the overflow level of the sink before the pipe goes horizontal. You ll need a way to prevent the sewer gases from coming up the pipe and stinking up your kitchen. The common island loop pictured here could become less popular now that the combination waste and vent option is legal again. A regular kitchen sink vent must rise at least 6 inches above the fixture before going horizontal.

Because a kitchen island doesn t have a wall to run a vent pipe the vent must be contained within the cabinet. The vent pipe is hidden within the wall. A regular kitchen sink adjacent to a wall has a vent hidden in the wall that connects to the drain. Obviously a vent pipe in a kitchen island can t do that.

Choose between an island vent or air admittance valve. Code expert glenn mathewson describes three ways to vent a kitchen island. Plumbing a kitchen island presents problems for venting because the sink isn t near a wall behind which you can hide the vent pipe. To do this you ll need either a vent that goes under the floor or an air admittance valve aav.