What is an Overflow Drain?

    What is an overflow drain?
      Overflow drains are secondary drains that work in tandem with primary drains to prevent an overflow or spillage of liquid out of some type of receptacle. an overflow drain is found in the bathroom sink. As with the bathtub, the presence of this secondary drain in the sink helps to prevent the basin from filling completely and possibly overflowing onto the surrounding floor. This simple design element can mean that the chances of water damage to the flooring and possibly baseboards in the room are significantly lower.