I want to install a discharge drain for my washing machine to go out of the house for irrigation use. Is the size of the drain pipe critical for this drain to avoid back splash of water into our laundry room. What is the minimum size I could use and is the configuration important? Could I use a pipe size similar to the current drain and once to pipe is through wall reduce to a smaller size like a garden hose to direct the water to where I want it?

Thanks for your help. Art

Hi! noclox, and welcome to AMHD :)

If your planning to use the washer pump as a pressuring device, you have to maintain the size of the discharge hose to your desired location, any reductions in pipe/hose size will result in black-splash, and will ruin the washer pump. You can check at a big box for sump pump hose/PVC pipe, and adapters/clamps to mate with the washer discharge hose.

If you wanted to make this automatic you could pump to an outdoor barrel, and let it drain by gravity by garden hose to your desired location.

Is the washer below ground level? If it is, it may not happen right away, but, again you take the chance of ruining the pump.

Regards... KUXJ

I want to install a discharge drain for my washing machine to go out of the house for irrigation use. Not too swift a idea if you bleach your whites. Bleach contains chlorides and plants don't like that. Plus the soap will leave a scum on the dirt that's based in fat. This will prevent sunlight from getting to the plants you wiah to water. A much better idea would be to drain your gray water into a dry well.
Do you need instructions on how to build one?
Regards, Tom