Before I get too much into planning, what should I be aware of in this existing configuration?

[ShelzMike]

I am remodeling the only bathroom in our 3 x 1, 980 sq. ft. home. It was built in 1943 and the original configuration still exists of the plumbing, but the materials have changed over time. Previous owners before me had made repairs, so the makeup is as follows:

Waste stack is 4" cast iron. The single vent is galvanized for the vertical portion, but PVC for the rest of it (both the vertical portion that goes to the basement as well as the horizontal leg to the vertical main vent. All PVC except the traps are 2". The traps are 1.5" currently. Note, for simplicity in my SketchUp animation, everything is either 2" or 3" so I could get it together quickly.

I am in VA, so IPC and no locality code deviations exist.

As you will see, the bathroom and the kitchen share a wall. Everything is sharing a wet vent in this setup, but one thing I know I will be changing is removing the sani-tee between the sink drains and installing a double wye, thus eliminating the horizontal drain/vent connection and running a new vent horizontally, then turn to tee into the existing vent so that it is above the flood level rim.

I also think the tub vent is too long before it reaches its vent. It is also too far below the joists, which I will fix. The one thing I want to try to avoid is getting in the attic to attach any venting if at all possible. I recently had my attic reblown and don't want to crush down any of the insulation, plus it is super tight up there and hard to work with.

One final note, there is a washer that is connected into the stand pipe in the basement and while it looks a bit rough, in my opinion, I actually haven't had any issues out of my system the entire 16 years we have lived here. No smells nor any backups or drainage issues. That being said, I do want to completely redo all of it except the last vent from behind the toilet through the roof. I am looking for some advice on what I should look out for, be aware of, anything that is no longer up to code, etc.

This animation is of the Sketchup model I made of my bathroom and kitchen. It is all accurate within its measurements (as in yes, my studs really are that unevenly spaced in the batrhoom walls as are the joists and yes the toilet bend really is that tight against that one joist. The animation focuses on several view angles, so if you watch it all, it will move to give a good overview. Thanks!

 

[Terry]

Nothing is correct in that layout.

The downstairs fixtures need their own venting before they enter a main stack.
The shower is not vented up stairs.
A kitchen sink can't wet vent any bathroom fixtures.

 

[Sponsor]

 

[ShelzMike]

Oh, is that all? Seriously though, I knew it was not up to code - many things in my home are not because a lot has changed since the 40s. You are confirming what I suspected other than the sink being unable to be a wet vent for bathroom fixtures. I believe I have an idea how to rectify all of this. I will put together my thoughts in another model and post back when finished.

for the basement - can the utility sink and the washer share a single vent so long as it is before it enters the stack? i.e, can I have the drain essentially the way that is currently is, but add in a vent between the standpipe and the tee where the drain for the washer and utility sink meet? In other words, can the utility sink have a very short wet horizontal wet vent? Thanks for the support and assistance!

 

[James Henry]

I drew this in SKETCHUP.

 

[ShelzMike]

I drew this in SKETCHUP.

Thanks for the ideas. They are similarly in line with what I was thinking; however, the vent tie in from the utility sink may be a problem as there are undrawn obstacles that wpd make that hard at that height or really at any height above flood level. I may be relegated to an AAV for the utility sink which I'd like to avoid, but isn't that big of an issue since it will be very easily accessible.

I'll be finishing up my altered SketchUp model and posting back to make sure I have a good path forward. Thanks again!

 

[Terry]

the vent tie in from the utility sink may be a problem as there are undrawn obstacles that wpd make that hard at that height or really at any height above flood level.

Perhaps that line could cross in the joist space where you would have more room.

 

[ShelzMike]

OK. Finally finished the rework planning and I think (hope, at least) that I have got it right. I will say I completely respect the pros when it comes to planning and implementing. This was way more challenging that I had anticipated, mainly due to the location of obstructions, weird angles, etc.

A few things to note. I chose an AAV in the wall beside the tub/shower because I have a low slope roof and the attic is full of blown in and I felt this was a more appealing solution. It will, of course, be in a box with a grate cover to allow it to work and to be maintained.

The utility sink drain is slightly wonky with that extra 1/16 in there, but I couldn't figure out how to do it and still get that vent vertical where it is located which is literally the only place it could have gone really. If you look back at the original video, the soil stack is actually all CI. I had planned on cutting it about 24" above the slab and Fernco on 4" PVC. Then, I realized I had that CI wye at the very bottom which made that incredibly difficult to do. Finally, I decided to remove the lead caulk around the very bottom bell at the slab and I will use an appropriate fernco donut which made it MUCH easier to work.

Also, falls are not represented here on the horizontals. I, of course make sure everything has the correct fall, but it is just too much of a pain to try to actually create that in Sketchup. As mentioned before, I chose not to go into the joists because they are quite high in the basement and no one is ever going to drywall that high up. Much easier and, dare I say, cleaner this way.

Thanks for taking a look!

 

[James Henry]

Looks good. Turn the wye clean out almost vertical on the stand pipe. You don't need a clean out on the laundry sink. Use a double fixture fitting on the first floor sinks. You don't need clean outs up high unless you want them, their a pain. you can snake through the tub and sink drain. I would consider putting the laundry sink drain over the stand pipe drain, you would have to do the math.

 

[Plumber01]

Wouldn't pass inspection in my area due to:

-utility sink and washer vents should revent above the flood level of the toilet on the first floor
-vent takeoffs using santee's on their backs

 

[James Henry]

Wouldn't pass inspection in my area due to:

-utility sink and washer vents should revent above the flood level of the toilet on the first floor
-vent takeoffs using santee's on their backs

I just saw that and was going to edit.

 

[ShelzMike]

Looks good. Turn the wye clean out almost vertical on the stand pipe. You don't need a clean out on the laundry sink. Use a double fixture fitting on the first floor sinks. You don't need clean outs up high unless you want them, their a pain. you can snake through the tub and sink drain. I would consider putting the laundry sink drain over the stand pipe drain, you would have to do the math.

I really appreciate the feedback. I actually had the cleanout on the washer drain vertical at one point. Most likely, it got accidentally selected when I was changing something else and flipped and I didn't catch it. Needless to say I wouldn't have installed it like that! I did get a feeling I might be adding too many (well, unnecessary really) cleanouts so leaving a few out will be perfectly fine with me.

As far as the double fixture fitting, perhaps I am misunderstanding or an missing something, but I thought that is what I have already in the design.

Ah...the utility sink above the laundry dilemma. So I really tried to make it work that way, but it put the trap quite a bit too high for this sink. I have the standard utility sink on the metal legs and it only stands 18" to the bottom. With 2" pipe, I would essentially have to raise the sink up, I guess by putting it on top of some sort of blocking at the feet. I suppose I could do that if it is more of a standard design or more desirable. The only other option is to combine the washer and utility sink into a single branch. I think that is ok if I am understanding the code (IPC) correctly, but not good form. That being said, I'd venture to bet that the way I have it is better than combining them. I'll see what I can do with it. As long as it doesn't put the sink higher than the window, I think I am make it work. I also realize that I would save a little more than an inch by using a street 4 x 2 santee, which is actually what I will use.

EDIT: Changed fitting name

Wouldn't pass inspection in my area due to:

-utility sink and washer vents should revent above the flood level of the toilet on the first floor
-vent takeoffs using santee's on their backs

I wasn't even aware needing to revent, so I am really glad I am going through this process and thankful for you guys willing to help me out. I have an idea on how I can accomplish that without too much trouble actually.

So for the santee's I thought this was OK to do in this instance because they were for venting only. That being said, I can change the ones that are on their back. What is preferable in place? a wye + 45 or a combo?

 

[James Henry]

I just saw that and was going to edit.

It's not life or death to have the laundry sink first, just considering the laundry suds coming up in the sink. Not a deal breaker.

 

[James Henry]

I really appreciate the feedback. I actually had the cleanout on the washer drain vertical at one point. Most likely, it got accidentally selected when I was changing something else and flipped and I didn't catch it. Needless to say I wouldn't have installed it like that! I did get a feeling I might be adding too many (well, unnecessary really) cleanouts so leaving a few out will be perfectly fine with me.

As far as the double fixture fitting, perhaps I am misunderstanding or an missing something, but I thought that is what I have already in the design.

Ah...the utility sink above the laundry dilemma. So I really tried to make it work that way, but it put the trap quite a bit too high for this sink. I have the standard utility sink on the metal legs and it only stands 18" to the bottom. With 2" pipe, I would essentially have to raise the sink up, I guess by putting it on top of some sort of blocking at the feet. I suppose I could do that if it is more of a standard design or more desirable. The only other option is to combine the washer and utility sink into a single branch. I think that is ok if I am understanding the code (IPC) correctly, but not good form. That being said, I'd venture to bet that the way I have it is better than combining them. I'll see what I can do with it. As long as it doesn't put the sink higher than the window, I think I am make it work. I also realize that I would save a little more than an inch by using a street 4 x 2 santee, which is actually what I will use.

EDIT: Changed fitting name




I wasn't even aware needing to revent, so I am really glad I am going through this process and thankful for you guys willing to help me out. I have an idea on how I can accomplish that without too much trouble actually.

So for the santee's I thought this was OK to do in this instance because they were for venting only. That being said, I can change the ones that are on their back. What is preferable in place? a wye + 45 or a combo?

What he's talking about is, instead of connecting the stand pipe vent in to the vent under the floor. Keep going through the floor and tie the vent in 42" above the floor into the toilet vent.

 

[Plumber01]

So for the santee's I thought this was OK to do in this instance because they were for venting only. That being said, I can change the ones that are on their back. What is preferable in place? a wye + 45 or a combo?

Yes a wye and 45 or a combo.

You did revent, you just did it under the first floor. As James said, keep on going up to the first floor and tie in at 42".

 

[Mliu]

Wouldn't pass inspection in my area due to:

-vent takeoffs using santee's on their backs

Is that a local code? Because there is nothing in the IPC that prohibits a sanitee on its back for dry venting.

 

[Terry]

Is that a local code? Because there is nothing in the IPC that prohibits a sanitee on its back for dry venting.

Here it's a code. I believe it's in case someone mistakenly decides to later put waste down it. It's more preventive.

 

[ShelzMike]

OK, second (and hopefully final) edit. I think I am all good now. I was able to get the sink drain below the washer drain. I would have used street santees in the stack anyway,but I wasn't using them in the drawing. Once I switched to those, it lined up much better.

So is the verdict on santee's on their back for dry vents that it is technically allowed by IPC (which is what I fall under) but that it is just sort of bad form regardless? Mainly asking because the tub vent gave me a hell of a time getting something that worked since it was offset a bit. I could, I suppose, changed the angle coming off the trap for the tub to have it run underneath the vent more perpendicularly. Since it is a dry vent, is the way that I have it acceptable, albeit slightly convoluted? I get it is too many sharp bends for any waste draining, but if it is just for air, it shouldn't be an issue, right? If I can use a santee on it's back here, it would be much easier (as it was in the previous video).

I also had to add in a little bend to the utility sink vent to get the drain to connect up to the stack with the weird angles and to deal with the obstructions that are in the way. I tried so many different way, but this is the only way it would work and not be even more complicated than it looks here.

 

[Terry]

The tub/shower would be better if the line were under the vent so that it can rise vertically. They don't allow a flat vent below grade anymore. After the vent is picked up, then you can 45 or 90 for the trap.

Tilting the combo at a 45 is also vertical, but vertical is easier to install.

 

[Mliu]

So is the verdict on santee's on their back for dry vents that it is technically allowed by IPC (which is what I fall under) but that it is just sort of bad form regardless?

I have not studied your particular design so I cannot comment on that aspect of this discussion. But regarding the sanitary tee on its back for dry venting, I'd have no compunction about installing one under the IPC. Not only is it not prohibited, but the ICC's published code commentary discusses sanitary tees used in this manner and specifically states that it's okay.

I understand the sentiment about installing a combo-wye in the event someone tries adding a drain to that vent pipe, but you can go crazy trying to design in anticipation of what someone might do in the future. I've done a lot of industrial electrical work and this topic is a frequent discussion among professional electricians. The bottom line is you design for what the requirements are now, not what they might be in the future.

Of course, if you wish to plan for future expansion and you're able to fit a combo-wye into your design, then why not?

 

[Terry]

My preference in answering questions here, since we're talking most of North America where things are somewhat similar, but may be done differently depending on your exact location, is to advise in a way that it meets any code requirement. That way anybody else reading and following along can copy what they see, and still get it right, even where they live.