View Full Version : Washer Drain requirements....

04-02-2005, 09:04 PM
Hi All,
I would like to move an interior washer/dryer to the garage. Its a single story house and garage is 32" below the interior floor.
My question is this: If I place the washer in the garage what is the minimum amount of drop required to go from the washer drain (inlet) to the water trap and then from the trap to the rest of the drain plumbing?
There is a 2" sink drain about 8 feet away (maybe less) and the vent pipe is easy to route in the garage. Assuming that the drain plumbing I plan to connect to is about a 12/14" below the interior floor, well that doesn't leave much drop for the washer drain.

My concern is that a backed up drain could result in the waste backflowing to the washer and or spilling in the garage.

Does anyone have any thoughts on this? If its a bad idea - feel free to call it as it is.


Randy A

04-03-2005, 12:41 PM
The drain needs 1/4" per foot slope. You also need a vent, the distance depends on the size of the drain line. The vent for the laundry tub may be too far away. Then, the standpipe for the washer needs to be tall enough. I'm not a pro, one of them can fill in the details.

04-04-2005, 05:39 PM
Remember that the washer must drain into a standpipe which is at least approximately at the height of the top of the machine. WM are gravity drain and if you lower the outlet hose, it will just drain out. You also need a minimum standpipe length, approx. 24" just to 'absorb' the pump output and not overflow.