I want to have two washing machines at home. I need to set up the plumbing and want to make sure I have the correct setup to allow for both washers to be used at the same time. For example, what diameter is needed, do I only need one vent for both, etc.

Hello Melendezml,

I would install two independent 2" drains, each with its own P-trap, draining into 3" main pipe. As far as vent goes, I would install 2" vent for each set up. Vents can combine into one 2" common vent at around 48" height, than combined with other vents in your house, or ran above the roof line

This is very helpful! Much gratitude.The current layout of the basement is as follows. There is a 3" pipe that is above the ground level that goes to the 1st floor. This is currently on the East wall of my house. This pipe currently has a T connector about 12 inches from the ground where the utility sink drain is connected to. I plan to cancel the utility sink and use this T connector for the washing machines. Should I add another T connector above the current one? The washing machines will be located on the north wall so it's perpendicular. I drew a sketch of current layout but don't see an option to insert image.Appreciatively,

Attaching image

In that case, I would run it as per enclosed drawing. You should be able to get away with 2" horizontal drain pipe if there is no option of running 3" common horizontal drain. Maintain 1/4" per foot slope. Riser should be 30" minimum in height. Connect to existing vertical 3" drain with combination of "Y" and 45 degree street bend fitting. Use either Long 90 Ell in the corner, or two 45 degree bends to make the turn. Vent can be connected to other house plumbing vent system ( here, be careful not to connect it to Sewer Ejector vent or discharge pipe ! ) Install Clean Out on the end of the horizontal run

Cut out the existing 3 x 1 1/2" "Y" in the vertical pipe. Install new "Y" fitting of appropriate size ( If using 2" horizontal pipe - then you will use 3x2 " "Y" ). Unless that vertical pipe moves up and down couple of inches - you will have to use Fernco coupling to make the final connection

Hope that helps

Milo