The washing machine in your home discharges water into a pipe, that’s usually hidden inside of the wall, called the stand pipe.
This pipe must be of sufficient size and height to be able to accept the high volume of water that is quickly discharged by today’s washing machines.
Since the early 2000’s, it’s been a requirement that the washing machine stand pipe be at least a 2″ minimum diameter pipe.
We often include the following language in our inspection reports, to advise our clients (who are buying older homes that may have smaller diameter washing machine stand pipes) to consider upgrading the size of their washing machine drain pipe, in order to prevent any future drainage issues:
It appears that the washer drain line may be undersized according to current standards (2″ minimum), and upgrades may be warranted. Newer washing machines often discharge a high volume of water, which may cause problems with older, undersized drain lines. If washer drain line problems are indicated, contact a licensed plumber for further evaluation.