Basement Laundry Sink / Washing Machine Standing Pipe

diy_ny

Hello,

I'm looking to replace my 1940's laundry sink with a new one. I have a cast iron p-trap and am looking to remove it once I receive the new laundry sink. I also want to add a standing pipe with a p-trap for the washing machine which is about 4 feet away because right now the drain hose is just going into the sink.

I was looking to cut right after the sani-tee and use a no-hub coupling with a pvc wye where it would go towards the standing pipe to the left of the picture and the other goes to the p-trap of the utility sink. Or cut the whole sani-tee and replace with couplings and a pvc sani-tee but Any other ideas?

Also, what are the IPC and UPC codes for how high the standing pipe must be? I am looking to put a laundry box and am hearing that 42" from floor but I'm also hearing that 18" to 30" from p-trap as well. Obviously, anything higher than the utility sink but not to high that the washing machine can't pump out the water.

The left pipe is a vent that goes through the roof and the right one is an upstairs kitchen drain.

Please disregard the sharkbite hot/cold suppply lines in the picture..they are temporary.

The laundry sink is attached. Thanks.

miatafrank

You're best to cut out that cast iron tee and put in two wyes or tees. One for the sink and one for the standpipe. Just make sure the stack (vertical pipe) is supported, you do not want it to slide down. Didn't check the code but generally the standpipe height is anywhere above the flood level rim of the new laundry sink. I would make it 2 inch pvc and have a p trap at the bottom of it. I like a double sink if there is room because the washer can drain into one side while the other side is free to use on its own. Good luck

EBEBRATT-Ed

Washing machines will pump to 6' , I would put the stand pipe just above the height of the washing machine. I would remove the old trap and install a Y go to the sink with it's own trap and to the standpipe with it's own trap

diy_ny

Thank you both for your thoughts and suggestions!!!

Alan (California Radiant) Forbes

The UPC wants the p-trap between 6" and 18" off the floor and the standpipe 18" to 30" long. Looks like you won't make the former which is no big deal.

If you're going to stack the fittings (one on top of the other), you should use tees as wyes will stop air flow from the vent.

The lower fixture (laundry tray) will be wet vented which is allowed by most codes.

Use 2" for your standpipe and make it as long as possible. New clothes washers have powerful pumps and I've seen them overwhelm short standpipes.

Don't know if a washer box is really useful as they are meant to be recessed into a stud wall and don't offer any clear advantage.

I would just screw drop ear 90's to your concrete wall for the hot and cold. Available in ProPress, PEX, copper, SharkBite......

diy_ny

Hey Alan. Thanks for the info. Right now my p-trap is 6" off the floor. But I'm sure it will change once I replace it. I will make sure it is between 6" and 18" from the finished floor. I was planning on using 2" pvc and looking to remodel my basement with studs which is why I would be using a laundry box. I dont plan on stacking them as the washing machine and laundry sink will be lateral to each other. I was going to use wyes for horizontal direction. One direction it would go to the stand pipe and the other to the laundry sink. Also, I've seen the drop ears for shower heads but never realized they could be used for supply lines.

Alan (California Radiant) Forbes

You can't use two traps on one trap arm, but I can't see it from my house.

diy_ny

Thank you for the knowledge.

diy_ny

@miatafrank - Any suggestions on supporting this vertical pipe? This is a very heavy pipe going up 1 story and a half through the roof.

pecmsg

There are any # of clamps designed to hold the upper piping. Is this something you want to undertake or call someone that knows.

You sound a little out of your comfort level!

diy_ny

@Alan (California Radiant) Forbes Just curious how would do dual sink p traps work? Do they have to be setup to be stacked (on top of each other) like in your sketch?

hot_rod

Maybe try unscrewing that old trap, fernco onto the nipple. Then you don’t have to worry about supporting the stack

diy_ny

Thanks hot rod. I was also thinking of cutting in the middle of the nipple and then fernco 2" pvc trap. But then for the standing pipe, I may have to come from the stack? 🤔

Alan (California Radiant) Forbes

On a double sink, you can use a continuous waste with one p-trap.

As you can see, the fittings take up a lot of vertical room, so you would have to raise the sinks a few inches.

As for the washing machine standpipe, I would tap into the kitchen drain and tie into the existing vent or add an air admittance valve if code allows.



Just so you know, the nipple coming out of the tee attached to the trap is 1½" and not 2".

It's a lot of work. Why don't you just drain the washing machine into the laundry tray?

STEAM DOCTOR

Is there a reason not to drain into the sink? Gives you the best buffer in case of backup.

Hilly

If the hub of that TY is pretty flat you could get the correct sized Fernco. Cut the nipple flush. Fernco makes a Socket x Pipe connector. So one side goes over a socket or hub and the other accepts a piece of new pipe.

diy_ny

@STEAM DOCTOR , I guess the consensus is to keep the washing machine drain hose in to the sink. I just thought it would be cleaner since I'm remodeling my basement. @Hilly yes this is what I'm planning to use. Thanks.

Alan (California Radiant) Forbes

I prefer a standpipe because yes, it's cleaner. The laundry sink can overflow if lint clogs the drain. But in this case, it's just too difficult to get a standpipe over there.

diy_ny

Got it. Thanks again Alan for taking the time especially for the sketches and everyone else's input!! I appreciate it!

mattmia2

If the porcelain is in good shape I would consider just painting that laundry tub on the outside and putting a new drain fitting and faucet. You'll never get a replacement that is as sturdy as that.

diy_ny

@mattmia2 ...It's true this is original and they don't make them like they used to.

diy_ny

Thanks everybody!