Hooking drain for new sink into toilet line

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cmac2012

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Redwood City, People's Republic of California
I'm remodeling a bathroom, it's almost doubling in size. In the garden level (built on a hill), it has a slab floor. Will have a new vanity, I figured quickly enough that I'll need to tie it into the toilet line somehow. Here's a pic of the toilet line as is:

IMG_0329.jpg


In this pic were my two choices at Home Despot. The upper one is more normal but it's too long for the space I have:

IMG_0333.jpg


I want to use the one on the bottom. Will be a snap to fit in place. I meant to take a pic of looking down into it. It's a bit odd the way the 2 inch line dovetails into the 3 inch curve. I worry that **** might get caught in it. I forget what this piece is called, I had it on screen a few days ago but I don't have the part (and the UPC code) with me now. I'll find that and take a pic tomorrow at the job.

Here's a crude drawing of the room and the opening I've since chiseled into the 'crete:

IMG_0373.jpg


The previous wall was just to the left of the new vanity. the door right there also. The toilet will be much nicer, a one piece Toto, an elongated - Ultramax ll I think. It will be 90 degrees spun around. I decided to send the sink drain to the toilet line as I want to move it two inches back so I can get that 12" from wall - will go for 12.25, I've gotten way too close for comfort once or twice.

My thought is that the sink is usually run briefly after every toilet use so if anything was lingering in that smaller space, another sort of flush would soon be coming.

But this is sort of weird, I've never seen anything like it done anywhere. Anyone know if this is OK?

*Edited to add*

This is in the Bay Area, it's way busy right now. Mega large dollars have landed on our shores with Facebook. I would normally bring a plumber up to do this but eveyone is busy as hell with more lucerative jobs. And I am a half-fast plumber. So why not I say? Hubless fittings done made me into a pro.

The shower used to be in the upper left hand corner. A tub is going in.
The shower line too close to the surface to send the sink that way. Wouldn't be able to get good slope.

**

Just found a listing for the part from Grainger. They call it a "3" x 3" x 1-1/2" 90° Elbow with Low Heel Inlet." Looks like mine but they say it's a 1-1/2 " fitting. Pretty sure mine is a 2".

https://www.grainger.com/product/MUELLER-INDUSTRIES-3-x-3-x-1-1-2-90-Elbow-with-3GUP4
 
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Need to use a shielded coupling, no fernco. I am not UPC as far as the drain for the sink. Rear outlet 90° not legal for drains in my area
 
Good call on the shielded coupling action. It wasn’t going to be far underground, I’m planning to wall off the fernco part of the line and just put gravel there, concrete everywhere else. That one spot between the toilet and the wall could be left as gravel easily enough. Can make the floor work.

*Breaking news*

Finally found some info on the suitability of that and doesn't look good, back to the drawing board:

P3005.1-quarter-bends-with-inlets-allowed-uses.jpg


http://www.homeownersnetwork.com/booktopic/drain-sewer/

But thinking about it more, it occurs to me that if I found a 4” elbow with 2” low heel connection I could use a 4” x 4” coupling and shielded are available in that, not sure about 4” x 3”. And indeed, such a coupling is available here:

https://tinyurl.com/y8r8alqj

They refer to it as:

4 x 4 x 2 Inch, ABS Drain, Waste and Vent Pipe 90 Elbow with Low Heel Inlet

I don’t want to be guilty of using something that is only appropriate as a venting connection in a manner that will cause grief that is only discovered after my new tile floor is in place. They do say “waste” but that’s not a detailed description.

The fact of it being 4” does ease some of my anxiety about flow issues with solids but I don’t want to go overboard with seat of the pants engineering here.

I’m not following what you mean by “Rear outlet 90° not legal for drains in my area .” It’s not a rear outlet toilet but I don’t think that’s whay you’re referring to.
 
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If you are putting a vanity beside your toilet why don't you tie a 3" x 11/2" tee into the 3" vent above your toilet. As long as your not real far away this is call a wet vent.
 
The vanity used to be next to the toilet. It was about as tiny as a bathroom can be and still have a shower. In my crude drawing, the vanity was where the nose of the toilet will be now. By turning the toilet 90 degrees, we are able to go with a long toilet and allow for more legroom, comfort. The drain for the new vanity is almost 8 feet away from the toilet drain now, and on the other side of the door. I'm going to vent it in large part through a cavity already in place for large ducting.

This house has some issues. I'm guessing 40s or 50s. Has knob and tube wiring but the newer red, black, white, and green insulated wire, not that old black brittle stuff.

Anyway, the duct cavity will make it fairly easy to tie into the toilet vent. It's connecting the drain that's giving me fits. In the graphic I found that rules out the elbow with lower heel inlet, it show a side inlet elbow that is acceptable for toilet use. If I can find one of those, I'll be a happy man ... I think.

*ETA* Here's a drawing of the old bathroom laid over my earlier drawing:

IMG_0376.jpg
 
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What you’re proposing is a bad idea and definitely not to code. I quest you can do what ever floats you boat. That should be tied in to drain after the toilet vent. That will require going deeper and opening more concrete.
 
What you’re proposing is a bad idea and definitely not to code. I quest you can do what ever floats you boat. That should be tied in to drain after the toilet vent. That will require going deeper and opening more concrete.

Uh-oh, that's not good news but I do need to get at the best route here. I have abandoned the notion of using the low heel fitting already. Was not comfortable with that. Presently I'm thinking to go with the upper assembly in the pic in the OP, the one above the low heel tie in piece. I figured a way to get it in in the room that I have.

But I'm having a hard time understanding why tying in before the toilet vent would be trouble. I'm planning to vent the vanity drain up above into the same toilet vent. The chances of the toilet being flushed while the sink is being drained are slim.
 
The two guys I wanted are too busy and my job is some distance from them, like 40 miles. The Bay Area drives me nuts that way. Word of mouth references will take you all over the place. I've been burned before by hiring an unknown plumber. And I've come on jobs in handyman mode where I had to fix work put in by a licensed plumber. Good plumbers are really good but hacks are out there.

I don't think this job is that tough. I will admit that my first idea was flawed. That's why I asked for advice, it seemed too convenient to be true, and it looked like maybe a headache waiting to happen. I hadn't seen that type of fitting before.
 
Okay Then, let's keep[ it simple. You want to turn the toilet and move the sink. Shower is staying as is?

Start by opening up the floor more to the old sink location.

dig it out and see which way the drain runs. best bet is to just run a new line over to where the existing sink is. You won't know what you have until you expose it. Labors free.
here's typical lay out of drain under slab depending on which direction it's flowing.

qqq.jpg
 
What you see in the slab I s “trap arm”. The toilet can be attached to it and nothing else until the waste from the toilet passes the vent. To do what you want to do you need to get on the downside of the toilet vent. That means you have to dig it up and get downstream of the toilet to add another fixture. Potentially you could “wet vent” the lav but it would have to be under 42 inches in developed length in 1 1/2 pipe or 60 inches in 2 inch pipe.(total length). If approved by your local authority. Dig it up and do it right or hack it in. It’s really an easy choice. Just more expensive to do right.
 
Sounds like good advice. A tub is going into the spot where the shower was, well, the drain is in the same vicinity, the room is about twice as big as it was. Here's a pic of that wall about a week ago.

IMG_0313_3.jpg


Note to self: take pics AFTER clean up.

The old vanity drain is above the black rubber hand grip on the Sawsall. It goes sideways to a main drain from above. This handles the kitchen which is above and behind this spot - it doesn't go straight down as the wall that contains the line is above the 8 foot concrete wall.

One small difficulty, this fellow is (was) a longtime bachelor. Point being, he bought this house years ago and rents out 3 rooms, generally, to pay the mortgage. He now has two housemates that use the kitchen daily, he and his new fiance as well.

But you may be onto something here, the best way might be to go to that drain and tie in. Would be easier for me though if I could tie into the toilet line. No interruption of service. Plus, the other side of the wall is home to the washer/dryer, would be nice to avoid dirt, dust, and rubble in that vicinity. He doesn't want to annoy his tenants too much.

The line that leads the shower to the sewer is way close to the surface, no way I want to try to tie into that one. But the shower drained just fine, no issues, so I'm pretty sure I can just shorten that, spruce it up a bit and put the tub onto it.

Is it just me or this a weird wall of plumbing? Not sure why there are two pipes in that bay above the red, trigger hand grip part of the Sawsall. They both tie into the vent going over sideways, I think one might be part of the washing machine drain. I've mostly ignored it so far as it doesn't pertain to me, but damn that's a weird looking mess.
 
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What you see in the slab I s “trap arm”. The toilet can be attached to it and nothing else until the waste from the toilet passes the vent. To do what you want to do you need to get on the downside of the toilet vent. That means you have to dig it up and get downstream of the toilet to add another fixture. Potentially you could “wet vent” the lav but it would have to be under 42 inches in developed length in 1 1/2 pipe or 60 inches in 2 inch pipe.(total length). If approved by your local authority. Dig it up and do it right or hack it in. It’s really an easy choice. Just more expensive to do right.

By the way, I appreciate the advice and I may need to open the floor on the other side of the wall and tunnel under it to connect on the far side of the vent. The cowboy in me keeps thinking it would work to attach it before the vent. I'm going up above to the same vent for the sink.

But clearly I don't want to discover a problem after I've put down a tile floor.
 
No need to open floor on other side of wall.
Blow out the floor in this room. dig down and find the horizontal line between the sink stack and the toilet.

Don't be squimish.
here's one I did because of some major roots had crushed ABS pipes.
This one was bad because the wall was on a major footing for a 3 story building and had some serious concrete.
The horizontal on my example was a bit deeper than normal.

Like I said before, you won't know what's there unless you open it up.
labor's Free when you do it yourself.


.

IMG_0313_3.jpg

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2012-05-02 008 (640x480) (2).jpg

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Holy Shiite, Batman. That is some serious root action. Never seen anything like that under a house, not that I've looked under many. Nothing stopping them I guess. One wonders if steel pipe would have done any better against those roots. Maybe for a while.

I appreciate the encouragement, but there's some history with the pipes that I haven't mentioned that argues against digging up the bathroom floor. About 2 years ago the kitchen sink started spilling out of the washing machine drain. All of the toilets continued working. Clearly not a root invasion in the main lateral. I power snaked about 25 - 30 feet down through the washing machine drain, finally broke it through. Standing water in the shower on the other side of the wall gushing down indicated that. Good God it stank. Rotten fish. One of his housemates, we discovered, had been treating the disposal like his own private garbage service - putting fish bones and guts down it. Judging by the amount of snake, looks like it broke through not far from the cleanout in the driveway (drawing at bottom). Seems weird but oh well, not going to dig up the garage floor.

The two upstairs toilets are on the edge of the house, the garden level toilet line, my toilet, points on the other side of the wall out to a long re-poured section from God knows when visible in the garage. It ends in a sort of T in the concrete surface. You can see where repair branches off to the left in the pic, who knows ...

IMG_0395.jpg


You can see the obvious diagonal lines in that pic continue up to the corner where it passes under the wall only more faintly, as cracks in the new surface. Must be a deeper pour, i.e. trench with pipe there is all I can figure. The upper boundary of the branch off to the left also visible.

IMG_0396.jpg


The main stack that handles the kitchen and the washing machine shows a turn out into the garage at the bottom where it enters the concrete.

IMG_0400.jpg


The how of this all hooks up under is a puzzle. The upstairs toilet stack, soil stack I guess is more accurate, disappears into the slab with no sign of further excavation.

My latest pipe dream (me make funny) is to go with this arrangement:

IMG_0333_2.jpg


but with a shielded coupling and enlarge all of my sink drain and vent to 2 inches. That way, the line would essentially have a wet vent at the point where vanity line enters, and the main vent attachment about 6 inches further down.

The wild card for me is the length of the entire vanity drain line + vent - about 21 feet from the toilet connection over, up, and back to the main vent above. I gather that reduces effectiveness somewhat. I dunno, I don't think this is code legal but short of someone draining a sinkful of water and flushing the toilet at the same time, seems like it would perform well. Correct me if I'm wrong, a vanity normally needs a 1.5 inch vent. A 2 inch has nearly twice the cross section area. 3.14 sq. inches for a 2", 1.77 sq. inches for a 1.5."

IMG_0405.jpg
 
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roll that tee above 45° angle for the vent connection.
 
Don't do it!! Any one hear leading cmac to believe it's okay to connect his sink to the closet bend of a water closet is crazy.

Now that you have more photos, your better option is to open the cut in the garage and run your sink line to that, down stream of the water closet vent.
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That root job was a bit extreme. There was a lot more to that job than I showed here.

IMG_0405.jpg
 
I definitely appreciate your input and I'm not trying to diss your POV here but I proceeded to hook it up as I had suggested I might and then did a temp install of the toilet to give it a test drive. Will be an extended test drive as the client wants me to have it working as often as possible so as to avoid using his tenants' bathroom upstairs. Fine with me, saves me time and hassle.

I reinstalled the older Gerber 1.6, don't want to be putting the one piece Toto in and out, no need to risk a mishap or wear and tear on that one.

IMG_0443.jpg

)


It performs well so far. I put in a cheapo 1 1/4 plastic trap at the vanity to watch the effect on the it while flushing. The water moves up and down a bit, maybe an eighth of an inch but clearly is not evacuated. I tried a test with my client pouring water into the trap as fast as it would take it while flushing the toilet, also good.

IMG_0441.jpg

I'm certainly not sneering at the theory involved, it was your cautionary note that led me to examine the issue closely. I've noticed in various aspects of recommended or code procedures that some over-engineering is often built in - safer that way.

In new construction I would not do it as I did here. But my client was death on breaking up concrete in the garage. He's a great guy all in all, his money is exceptionally green, and he gives me a lot of work. He's a Stanford mathematician and some of his ideas are actually sound.

My thought is that the business of not hooking to the closet arm is based on a few things - one would be an unvented sink, would likely have the water trap sucked right out upon flushing. Another would be having too many fixtures go that route.

In my case, the vanity will rarely be used at the same time as the toilet, and by going with 2 inch all the way - drain and vent anyway - I've provided for good ventilation.

One weird thing, I had to elevate the drain origin at the vanity in order to get 1/4 per foot while rotating the Y up to near 45 degrees on the closet arm. The line is above the concrete, not a problem as I'm going to put in 1 x 1-1/2 strips of PT and then 3/4 ply on that, then concrete board and then tile, so I can put breaks in the PT strips and run all of that over the drain line.

Sounds nutty I know, this bathroom goes into small flood mode in rainy winters, the back wall is the retaining wall, pressure builds up from over saturation and leaks in. I tried to talk him into a sump in the laundry area but he didn't want to do it. Just as well, running the evacuation line would have been a PITA.

We had already run a one inch deep channel in the concrete through a storeroom opposite the bathroom door in hopes of the water draining out to the area under the front porch. He already had a crude elevated plywood floor to prevent water damage of stored items. Now we are going to have some channels under the tile floor to route the water more reliably to that first channel.

A bit odd but I think it will work. It's not that much water, a gallon or two a day maybe.

I put a small dam just before the hubless connector, I'll keep concrete out that area, I gather it's not good to encase those in concrete, I'll just staple on some cardboard to complete it.
IMG_0446.jpg
 
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