New Washing Machine Drain

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zhens

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Hi all. I am planning to install a new washer and dryer in this space, and as I opened the wall this is what I found. The opposite side of the wall is a bathroom, with a sink and toilet on that wall.

My question is if I can tie in the washer drain directly to the 2" pipe, which I believe is the vent for the toilet...possibly from the second floor and this floor. Sharing via this picture may not be enough info to diagnose, but figured I'd start here.

Thanks

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Sorry, just saw it. And where are you wanting to out the washer. Right on the drain line for the sink?
Or directly into the vent line?
 
No problem - it didn't upload the first time. I'd prefer to put it directly on the vent line as it is 2" instead of the 1.5" from the sink.
 
Depending on how close the stool is. Could make the water in the stool bounce due to the force of the washer. And how high you are going to attach the washer drain.

Which if the water in the stool does bounce, will drop the water level in the trap of the stool. Could make potential for sewer smell.

But wait and see what one of the veterans on here has to say. Those are some concerns I have with you connecting the washer so close to the stool. And I could be full of it.
 
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Sink is directly on the other side of the wall, and the toilet is 2-3' to the side of that.

The plan is to tie in about 12" above the floor inside the wall with a wye, and then tie in the P trap and standoff.
 
But wait and see what one of the veterans on here has to say. Those are some concerns I have with you connecting the washer so close to the stool. And I could be full of it.

Thanks for the help. Like you say, I'll wait for the veterans before doing anything drastic :)

Mods, if this should be moved to general questions, feel free to move. I wasn't sure the best place for it
 
zhens, is there a basement or crawlspace under this piping. Justin is correct because if you wet vent into that vent the pressure of the washing machine will cause a blurp and possibly siphon other traps out. Honestly you should tie into a 2 or 3" sanitary line.
 
zhens, is there a basement or crawlspace under this piping. Justin is correct because if you wet vent into that vent the pressure of the washing machine will cause a blurp and possibly siphon other traps out. Honestly you should tie into a 2 or 3" sanitary line.

Unfortunately this is in a tri-level, and this happens to be the portion on the slab. I've opened the rest of the wall up and this is what I've got now. I'm not certain that the 2" pipe vents both toilets, but that is my assumption. Is there a way to test that? The toilet on the opposite side of the wall in the picture (bottom floor) is directly below the toilet on the top floor.

You'll see in the attached picture that the cast iron pipe has a wye that lines up approximately with the toilet and rest of bathroom on the top level.
View attachment 16303
 

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Looks like you could use the large black stack to cut a tee or wye in for the laundry. But it needs to have it's own vent (or use an AAV if allowed by the inspection authority).
 
Washing machines can create a lot of force when draining-- so much so that there is some concern it might be able to rupture or damage the diaphragm in an AAV. But, one of the experts would have to weigh in.

I do think you would need a separate vent for the washing machine, but you could tie the top of it in to the existing vent a minimum of 6" above the flood level of the highest fixture. I just don't know where that is in this situation. The trap arm would need to be at least 4" long to avoid creating a crown vent.

IF an AAV can be used, it would have to have good airflow and be accessible for replacement/maintenance.
 
Thanks all for the input. Unfortunately AAVs are not permissible in Kentucky (as far as I've been able to read).

Below is another diagram. If I understand correctly, I would not be able to tie into the existing vent at this height (as I've drawn out here) if the toilet from the top level is also venting into this stack. Is that correct?

As shown on the photo, Approximately 2' to the left of the large pipe is an exterior wall. Apart from tearing everything apart to find the original vent stack, is it possible (advisable?) to vent out to the exterior?

Finally, reading through KY plumbing code book I found the following. Does this make all of the above moot?

Section 4. Washing Machines, Automatic, Residential (Old Buildings). An automatic washing machine installed in an old building, shall be connected to the house sewer by the use of a four (4) inch cast-iron P-trap, placed on the outside of the building on the opposite side of the wall of the washing machine. The trap shall have a vented cover extending three (3) inches above the grade line. A four (4) inch by two (2) inch tee shall be installed in the inlet side of the trap with a two (2) inch waste pipe extending into the building through the floor to the height of the washing machine. All waste piping shall conform with 815 KAR 20:080.

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How old is this place you are fixing up? It sounds like it is suggesting that you run a new vent pipe outside of the house and that it assumes you are working with cast iron.

I'm not sure on how the fixtures tie together on a multi-floor vent stack. I'd have to look it up and see. It's beyond my knowledge (since there aren't many multi-story homes in my area and I focus mostly on single floor homes). I'm hoping an expert can weigh in and help.

I wish I could be of more help.
 
This home was built in 1964 and the large pipe in the picture is cast iron. It has a cleanout in the basement before it goes under the basement slab. I appreciate the time you've spent on this.

Should I put this over in the main forum to get some input from an expert?
 
Let me see if I can flag someone down to help. This seems to be in the appropriate section.
If nobody answers here, you can always try the plumbing section of our sister forums houserepairtalk.com. It tends to have more activity.

Edit: I've posted in a couple of places to see if someone can help.

A thought though: Since you are near the exterior wall-- if the wall is not masonry and you can safely put a hole in it, you might want to put the vent out through the exterior wall and run a new vent just for it along the outside of the house with either ABS or PVC (and paint it to protect it from sun damage).

You could run the vent straight up from the drain to reach at least 6" above the flood level of the washing machine, then have an angle to take it out through the wall (making sure to slope up at least 1/4" per ft), out the wall and then straight up. If there is a soffit (roof overhang) then you have to route around it and terminate I believe about 18" to 24" above the roof (depending on your state codes-- I can never remember the termination point). It can't be near any air intakes or windows though.
 
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Cut the wye into cast iron stack, but turn it to the right side. Bring the p-trap outside the wall.
Take the vent up and over to exiting vent as long as the horizontal is above flood rim of the sink.

connect vent with santee inverted, sweep going up.

To avoid the high water volume effecting the toilet or suds if you have room install a laundry tray sink and dump washer into that

OR

just change the santee for the exiting sink to a double fixture tee and put in a laundry tray sink.
Dump washer into laundry tray sink.

already vented and buffers any water surge into drain

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