[pirogueguy]

Hi,

I've perused the various question and answers for washing machine stand pipes overflowing, adjacent sinks filling up etc. I've found a number of good solutions, however, I would like to get some opinions / suggestions for my particular instance.

Background Summary

- 30+ year old single story house, brick, w/ concrete slab

- 2" cast stubbed with 1 1/2" copper is the majority of the plumbing

- 1 1/2" washing machine drain stack ~34" tall

- recent minor remodel of the washer dryer area (and hence the problems now!)

- fierce, head-strong, weekend warrior, DIY type w/ LOTS of PVC experience and some copper fitting/sweating experience -- (I've got NOTHING when it comes to cast!)

Problem Summary

We've owned this house for approx. 15 years, our original washing machine (older, lower gpm pump, etc) did not cause any REAL issue. Now, 3-5 years ago, along comes the new washer... Now, at the time, this was not an issue either. We had two deep tub style sinks adjacent to the washing machine that would fill about halfway with washing machine waste water when the washer would empty. The water would drain out fairly quickly afterwards and was not a real problem.

My wife and I have recently decided to re-do our laundry room and have now changed the dynamics of the whole drain situation! We took the two deep sinks out, and replaced them with a single shallow 24X24 sink (my wife's wishes... <drone> MUST PLEASE WIFE... :D ). Now, since we've changed the drain height of the sink (and of course the volume associated with the removal of the two deep tub style sinks), now we started having consistent overflows from the washing machine drain stack. I've put one solution to use that I found on the AskMe site, and I'm using a 'fernco' type coupler between my drain stack and the washing machine drain line. This at least keeps the overflows from occurring. Now, since the volume of the washing machine is still too much, I get about 2-3 inches of water that backs up into our new shallow sink. Otherwise, everything is great!

Also, just for clarification, I actually own a mechanical roto rooter and have 'roto-rooted' the line on a couple of occasions. I never find any blockage.

Question begins here...

I would like to re-do this so that:

1. I don't experience overflows on the stand pipe
and
2. So I don't get water backing up into my laundry sink

Now, with this being said, I really don't relish the idea of busting concrete, and/or re-doing
the entire drain to the outer wall (and then tying into my existing drain-line some 50+ feet
away).

I've attached a couple of pics (see attachments) of the existing plumbing, and would like to see if anyone has any suggestions.

For starters, it appears to me that the stack / air vent is not set up properly. I can help but wonder if part of my issue is not getting enough air into the line to allow the water to drain out... Shouldn't the air vent tie directly into washing machine drain line with a sanitary-T? Also, would there be any issue in using a larger line in the wall space (say 3") in order to allow the washing machine volume to drain? I've even considered using multiple 3" pvc pipes set vertically next to each other to allow for the washing machine overflow (see image 'proposed' in attachment).

Any thoughts or recommendations on this would be greatly appreciated. If I've left something out, please let me know and I'll fill in any blanks!


Thanks!

[doug238]

Just below the sanitary tee for the laundry sink, cut in a straight 2" sanitary tee and bring it over to under the 1 1/2" copper piping- install a 2" pvc trap and replace 1 1/2" copper with 2" pvc to box. use 2" fernco couples and cut the cast iron with a corded reciprocating saw on low speed with a lenox 656-r blade, keeping the saw held firmly against the cast iron pipe. Install a cleanout tee looking out through the wall above the laundry sink tee. Cap or plug old washing machine pipe going into floor. It has a trap under the floor.
Uh, your drawing is , uh, not a good idea. You should edit it from your post. The pics helped a lot.

[pirogueguy]

Thanks for the info Doug! Sorry - for my 'in-g-eneering' on the drawing... I was racking my brain for anything. I'll get to work and let you know how it turns out! Thanks again!

[pirogueguy]

It's been awhile since I posted this question, and for those folks perusing this site for these types of issues... I felt I should post a follow up.

I had a friend advise a plumber friend of his that would help me troubleshoot my problems (ALWAYS good to know a plumber friend!! ). He said this was a fairly common problem in this age house. He said the common way to plumb this age house was with 5' sections of 2" cast iron pipe. Over time, the pipes - heavy as they are, will sag and the joints will begin to collect 'stuff' and will cause a partial blockage. He advised that I had two options: 1. Try cleaning out the line again to 'buy' some time, 2. re-run a new line and completely replace the old line.

So, with option 1 in mind, I put a single cutter blade on my 80' electric roto rooter, and a water hose and climbed on my roof to roto-root the line. I took it really slow, almost the full 80' down, and on the return too... I stopped often and ran as much water down the line as I could. On completion, I hooked my washer back up, filled the tub and went to the spin cycle to dump the water... waiting... waiting... no back-up!! A little over a year now, and it's been working fine!(knock on wood!! ) If it begins doing this again, I'll be back on the roof!

[Milo Dolezal]

From the posted photos, it appears like you have no P-trap. You have to install one. Also there is no vent. Absence of vent slows process of draining. See if you can rework the drain/vent situation and connect with new vent into existing someplace in the ceiling. If not, you could install AAV vent. But since AAV vent cannot be covered up, you would have to install removable, fake , A/C register in front of it so it can breathe. Also, install Clean Out directly on top of the Cast Iron pipe.

However, that Cast Iron doesn't look to me as 2" pipe but more like 1 1/2". Today's washers require 2" drains since they have very rapid and powerful pumps emptying washer in matter of few seconds. Small pipe cannot absorb so much water in such a short period of time.

You may want to run new horizontal drain all the way to that 2" Cast Iron (shown in the photo all the way to the right ). That could be your best bet.

[Milo Dolezal]

Looking at you photo again: that recessed box is too low and has to be raised to accommodate correct height of new stand pipe and trap. Now, it is about 33' high to the bottom edge. Raise it so the bottom edge is 41". It will end up right above the w/m control panel.

[doug238]

Milo, in those days plumbers usually never forgot a trap. The trap is below the floor.

[Milo Dolezal]

Dough: I would not be so sure about it.. .

Once you take it apart, look inside the C.I. pipe and see if there are couple of inches of standing water. If positive, than you are correct.

We always install trap above slab in new construction. If I placed trap below slab, Inspector would have me take it out and reinstall above the floor.

That's where my comment is coming from...

[doug238]

In the atlanta area the trap is typically below the floor. In Florida we also put many below the floor.

[Milo Dolezal]

That's great... Thanks for letting me know... One less thing to worry about...

It just proves to me that installation practices, and Code requirements, change with geo-location...

[speedball1]

Just to chime in. In the Tampa Bay Area we place the san tee and trap as close to the floor as we can and run the stand pipe up a few inches over the washers flood rim. This usually works ot to 36" or so. Cheers, Tom