A few questions on bath remodel: replacing cast iron fittings with PVC

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Temp945

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Hello all,

I am currently remodelling my 1960s "Jack and Jill" bathroom. I've already replaced all the old galvanized steel supply lines with ProPex. I'm not a pro, just an avid DIY homeowner.

Now I have a few questions on how to redo the DWV lines for 2 new PVC toilet flanges and the new PVC shower drain. I am grateful for any help and advice!

I am changing the bathtub to a tiled shower and will relocate the drain to the middle of the shower floor.

The 2 toilets and shower currently have the original cast iron fittings attached to their flanges which then transition to newer PVC lines and connect to the plumbing stack.

I have drawn a diagram showing how the 2 toilets and bathtub currently drain to the plumbing stack as well as another diagram showing proposed changes.

Questions:

1. Since I have to relocate the shower drain anyway, would it be a good idea to re-route the shower line to the 4" toilet line to provide additional drainage water for the low-flow toilet? As the diagram shows, the shower currently drains downstream of both toilets. If I did do this re-route, would it be accomplished by using a wye fitting attached to the 4" toilet drain line and then capping the existing 2" wye connection?

2. What is the best fitting to use to connect the new toilet's PVC drains to the existing PVC? I have attached a photo showing the existing PVC wye that connects both toilets to the stack. Should I cut off part of the existing PVC and add a fitting, or should I just remove the coupling and attach a length of 4" PVC with a hub connection here?

3. As shown in the diagram, there is currently a single cleanout upstream of the plumbing stack, under the toilet on the right. When I replace this section, is it required to replace this cleanout? If so, what is the best way to integrate a cleanout here?

4. The toilet on the left side of the diagram does *not* currently have a cleanout. Does it need one?

5. There is currently a condensate line that runs from my central HVAC closet to an outside wall of the crawlspace. The installer did a poor job planning this and there is an unavoidable belly in the line. I could re-route this condensate line to connect to the plumbing system somewhere instead. Is this OK to do, and if so, where would be the ideal place to connect the condensate line?

6. Is there any reason to replace the cast iron vent pipe that goes through the roof with PVC while I'm doing this? I will have the walls open so I will have access to it.

Thanks so much for reading! Any advice is appreciated.

Plumbing System - Existing_(Medium).jpg

Plumbing System - Changes_(Medium).jpg

Plumbing System - Toilets_(Medium).jpg
 

wwhitney

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Hello,

1) Short answer: no. Long answer: I'm not very familiar with the IPC (the plumbing code Florida uses), but I'm not sure that your venting arrangement (three horizontal fixture drains coming together to a single stack connection) is compliant. Perhaps it is as a "single stack vent system." If you haven't had any problems, then since it's been working OK, I would just leave it as is.

2) I was going to suggest just removing the shielded rubber coupling and adding a PVC coupling, but I see you have a PVC coupling or some reducer fitting just downstream of each shielded rubber coupling. So I think you'd be better off cutting through the PVC pipe just downstream of that fitting (you can use the hub as a visual guide to cut it square).

3/4) Don't know, but you could try reading the IPC section on cleanouts:
https://up.codes/viewer/florida/fl-plumbing-code-2017/chapter/7/sanitary-drainage#708

5) Attaching a condensate line to the sanitary drains needs to happen upstream from a trap. So the easiest way to do it if geometry allows is to use a sink tailpiece on a lavatory that has a branch inlet, similar to how a dishwasher can be connected. Using a dedicated trap could be problematic if there is a season where there won't be condensate, since the trap could dry up.

6) Don't know

Cheers, Wayne

branch-tailpiece-for-dw.jpg
 
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Temp945

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Wayne, thanks a million for your detailed reply. And double that thanks because you previously helped me with a question on the forum about sizing the supply lines for the shower :)

1) I did some reading on the "single stack vent system" you mentioned, and I think I have determined that my 1960s plumbing job is indeed a "single stack" system, also known as a "wet vent system", the code for which is laid out here:
https://up.codes/viewer/florida/fl-plumbing-code-2017/chapter/9/vents#912
And a layman's description is here:
https://www.pmengineer.com/articles...ct-the-philadelphia-single-stack-counterpoint
Based on my reading, it appears that the existing plumbing system as installed is compliant in terms of venting and I can safely just replace the cast iron fitting with PVC.
The code also confirms that, as you said, I should *not* tie the shower in to the toilet drain because the code states that "each wet-vented fixture drain shall connect independently to the horizontal wet vent."

2) If I understand you correctly, you mean to cut each fitting off and attach a new fitting as indicated by the arrows in the below photo, correct? Should I just purchase two lengths of bell-end DWV pipe to attach to the cut ends, or would it be better to use a 4" coupling here?

Plumbing System - Toilets_(Medium) - Cuts.jpg

3/4) Thanks for the link to the section on cleanouts. If I understand correctly, the the right-side toilet (in the diagram I drew) will need the cleanout replaced. It also seems that the left-side toilet will need a cleanout added. I was planning on using a "wye & 45-degree elbow combo" with a cleanout adapter to connect the toilet to the horizontal line, but then saw this thread which recommends against this practice:
https://terrylove.com/forums/index.php?threads/cleanout-for-toilet-in-crawlspace.69845/
However, my googling suggests that this seems like one of the most common ways to add a toilet cleanout. Do you have any thoughts?

5) Your explanation makes good sense. Unfortunately my HVAC's location does not allow for a connection upstream from a sink or shower trap. The AC produces condensate for about 8 months of the year here so I'm not sure if a dedicated trap would dry out or not during the short winter season. However, I am anticipating installing a dedicated dehumidifier and tying its condensate line into the AC condensate line, and the dehumidifier would produce condensate during the winter months. In this case, it sounds like installing a dedicated trap on the condensate line and attaching to the sink branch (very top of the diagram I drew) should work.

Thanks again!
 

Reach4

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5. There is currently a condensate line that runs from my central HVAC closet to an outside wall of the crawlspace. The installer did a poor job planning this and there is an unavoidable belly in the line.
Outside sounds nice. I would consider adding some liquid chlorine bleach or bleach solution maybe once per year to kill possible growths. A tablespoon of bleach, or a tablespoon of bleach into a cup of water sounds about right. Do you have a good entry point for the bleach into plastic rather than metal? A funnel with an extension may help.

Bleach is bad for plants, so you might want to take that into account.
 

wwhitney

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1) I think I agree, but I'm not willing to commit due to unfamiliarity.

2) Either way would be fine, I'd get one 4" section of pipe and then one or two coupling depending on whether the pipe was bell end. (Well, plus an extra coupling in case I made a mistake. :)

3/4) I have no opinion. I've done the combo/cleanout adapter vertical to horizontal turn before, but never directly below a toilet. Hopefully it won't cause me problems farther downstream. You could always go with closet ring - 90 - upright wye (wye plus street 45 resulting in two parallel inlets) rolled 45 degrees off flat - cleanout adapter in upper upright wye inlet. Or you could omit the cleanouts because you can always pull the toilet.

5) I think getting the condensate outside would be preferable to a dedicated trap on the sanitary drains (and for the latter case, take a look at 802.1.5 and nearby). If the belly on the existing line is required to get under an obstruction, is there no way to get proper drop from the obstruction to the exterior outlet? Move the exterior outlet lower?

Cheers, Wayne
 

Temp945

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3/4) The existing cleanout (photo below) is installed just after the 90. I just realized that I cannot install the cleanout directly below the toilet because there would not be enough access to it due to the exterior crawlspace wall about 12" away. The code you linked to previously states 18" of clearance is required. I have drawn a diagram of what I think your suggested cleanout strategy is below - is this correct? I like the idea of the cleanout being at the top of the drain so it cannot accumulate solids, but wouldn't the 90 in front of the cleanout block access into the cleanout? I'm wondering if I should just install the cleanout as it currently appears.

Plumbing System - Cleanout_(Medium).jpeg

CCI07082020_(Medium).jpg

5) Unfortunately the belly on the existing line is required to go under a floor beam and then up and over the plumbing stack before exiting the exterior wall through a crawlspace vent hole. Even if I drilled a lower hole on the exterior wall (and I'd rather not), the drain lines would be in the way of the condensate line following a lower slope. I could just deal with the belly and plan on regularly flushing the line, but I'd prefer to install the condensate line so that it is less prone to blockages and backing up.
 
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Reach4

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3/4) The existing cleanout (photo below) is installed just after the 90. I just realized that I cannot install the cleanout directly below the toilet because there would not be enough access to it due to the exterior crawlspace wall about 12" away. The code you linked to previously states 18" of clearance is required. I have drawn a diagram of what I think your suggested cleanout strategy is below - is this correct? if so, wouldn't the 90 block access into the cleanout? I'm wondering if I should just install the cleanout as it currently appears.
I don't fully understand what you are asking, but I don't think that would affect my comments. Some people just lift the toilet if they need a cleanout. Some extend the sewer pipe and even have the cleanout outside through the foundation or sillplate.
 

wwhitney

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I have drawn a diagram of what I think your suggested cleanout strategy is below - is this correct?
I'm suggesting rolling the wye 45 degrees either way from where you've drawn (e.g. 45 degree up from existing), so it is half way between being in a vertical plane and being in a horizontal plane. That way it's not pointing at the closet bend, but is also up off flat.

5) Unfortunately the belly on the existing line is required to go under a floor beam and then up and over the plumbing stack before exiting the exterior wall through a crawlspace vent hole.
If the floor beam is dropped (like a girder) rather than flush (in the same vertical interval as the floor joists), could you go over the floor beam? Or can you exit via a different crawlspace vent hole?

Just dumping the AC condensate outside is much more robust than putting it in the sanitary drains, there's a lot less that can go wrong. Also, if you have solid buried gutter downspout lines, getting it to one of those would work.

Cheers, Wayne
 

Jeff H Young

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It can be kind of a big deal pulling toilet bringing a snake through the house to clear a stoppage if it re- occurs it really isn't fun. that black stuff getting on walls scraping off the caulk to re caulk and making it look like no one was there not fun for me, so just pulling a toilet yea no big deal for some. a little touch up paint . If it were being built new the option of pulling toilet for a clean out wont fly. I recommend a clean out if its reasonably doable , I wouldn't spend a day on it but a few hours possibly especially if its the main and there isn't a clean out in front. just a thought!

I would estimate 95 percent of houses built in ca ( over the last 35 yr ) that have A/c dump there condensate into the drainage system. If it does dump on ground pretty sure it required a drywell several feet of rock. the PVC condensate lines can plug but I dont think that going into a lav tail piece is bad idea . running water down with bleach good idea good maintenance for sure. If I had a sink close by that's where I dump in every single time . I prefer going to the sink but whatever is easier is ok.
 

Temp945

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I'm suggesting rolling the wye 45 degrees either way from where you've drawn (e.g. 45 degree up from existing), so it is half way between being in a vertical plane and being in a horizontal plane. That way it's not pointing at the closet bend, but is also up off flat.

Got it!

If the floor beam is dropped (like a girder) rather than flush (in the same vertical interval as the floor joists), could you go over the floor beam? Or can you exit via a different crawlspace vent hole?

Just dumping the AC condensate outside is much more robust than putting it in the sanitary drains, there's a lot less that can go wrong. Also, if you have solid buried gutter downspout lines, getting it to one of those would work.

Cheers, Wayne

I'm going to think on the problem a bit more and just focus on the bathroom remodel for now. The condensate line has been working fine but I don't like seeing the noticeable belly in the line - it's a problem waiting to happen.

Wayne, I truly appreciate your help and advice. I think I'm ready to tackle the bathroom remodel! Demolition starts tomorrow.
 

Jeff H Young

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the belly is near that coupling it kind of flattens out? not terrible but not desirable might as well stack odds in favor of trouble free operation minor adjustment. Your on a good track!
 
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