Moving a Toilet

[GatorHawk]

I'm in the process of remodeling my bathroom and moving fixtures around (house is on a slab). I really have two questions. 1) Can I just cap the old 2" shower line above it's tee, and 2) what is the recommended solution to move the toilet. I was surprised to find the toilet connects to the main via a tee vs a wye, so now I'm trying to determine if it is acceptable to use a long-sweep 90 (or a pair of 45s, but length between them will be limited) and run parallel to the main line to move the toilet. There is a 3 inch vent on the main sewer line, but I haven't excavated enough dirt under the slab to reveal its exact location (so not included on the sketches). I was hoping for an easy solution, but I really don't like the idea of an "S" turn with two 90s back-to-back (even if they are long sweep). Recommendations are welcome, and I do realize that another option is to break more concrete and cut out the section of pipe in question and install a wye for the toilet. Thanks.


Existing (not showing the 3" vent)

Proposed change...

 

[Terry]

You're allowed 135 degrees of horizontal change, so that works with the combo, which is similar to a wye with a 45.
And yes, a wye would have been better.

 

[Sponsor]

 

[Reach4]

Where does the lavatory drainage join in? That is often a way to provide wet venting for a toilet.
Was the tub vented?
What drainage is coming from the 4-inch before the toilet joins that flow?

 

[GatorHawk]

The lavatory for this bathroom is downstream from the plumbing shown in my previous sketches (I'm not sure how it's vented since I haven't opened up the walls yet), and the second bathroom is upstream. The old tub drain is not vented at it's connection to the main, hence the plan to cap it. The main line is vented via a 3" vent downstream from the old toilet (exact location unknown), with 2" wet vents at the new tub location and the second bathroom's lav. The 4" line goes straight through the house with a clean out at the back and front of the line.

For clarification, if I'm allowed 135 degrees of change, doesn't a 90 degree elbow that connects directly to a 90 degree tee exceeded that, or not because it's not turning back on itself?


Some of these branch lines are guesses since I can't see under the slab. The red box is the area I'm working.

 

[GatorHawk]

I just realized I wrote "verticle" instead of "vertical"...

 

[GatorHawk]

Until I can confirm locations by opening up the wall, it makes the most sense that the 3" vent is part of the lav drain in the bathroom that I'm moving fixtures (the sinks are not moving in this remodeled), and that the second bathroom's lav is a 2" wet vent for the toilet... But those are guesses at this point.

 

[wwhitney]

I would say the best solution is to break out concrete from just downstream of the old toilet to just upstream of your new bathtub tie in. Then you can replace that section of main drain and tie in the new fixtures in the normal fashion.

The sink at the top of your drawing needs to have a vent, either through the roof or an AAV (as Alabama uses the IPC, which allows AAVs). Then that sink vent can wet vent both WCs and both tubs, under the IPC. To wet vent the tubs, the traps have to be set at a height such that the trap arm can travel horizontally to connect to a horizontal wye or combo on the main line, with a total fall from the trap of not more than one pipe diameter, but still falling at 1/4" per foot. I.e. not like the drawings in your OP. If you are able to do that, you would not need a new vertical vent on the bathtub.

The sink in the lower (red-boxed) bathroom will need its own vent (as its trap arm is much higher than your main line), which can either be an AAV or tie into the 3" vent you drew just below the red box, at a height at least 6" above the sink flood rim. That assumes the 3" vent is a vent only and does not receive drainage from above.

Cheers, Wayne

 

[GatorHawk]

I know the BEST solution is to break out the concrete and replace everything, but the 4" main line is about 3 feet below the slab with a non-load-bearing wall directly above it. I'll have to excavate at an angle to get to it. And the hot and cold waterlines are between my access hole in the concrete and the 4" sewer. I know I can do it, but I really dread that course of action, which is why I was asking if the proposed solution in the sketch above is acceptable (albeit, not ideal). I'll make sure the lav is vented properly after I finish the demo and open up the rest of the walls (the 3" vent is only a vent; it's a single story ranch). The new tub is already installed and vented as shown in the plan sketch. I'm having to remodel this bathroom in pieces because I need to minimize the impact to my family during the remodel (it's still a functional 1/2 bath until I tear apart the rest of it).

I'll be remodeling the second bathroom sometime next year.

 

[Jeff H Young]

I know the BEST solution is to break out the concrete and replace everything, but the 4" main line is about 3 feet below the slab with a non-load-bearing wall directly above it. I'll have to excavate at an angle to get to it. And the hot and cold waterlines are between my access hole in the concrete and the 4" sewer. I know I can do it, but I really dread that course of action, which is why I was asking if the proposed solution in the sketch above is acceptable (albeit, not ideal). I'll make sure the lav is vented properly after I finish the demo and open up the rest of the walls (the 3" vent is only a vent; it's a single story ranch). The new tub is already installed and vented as shown in the plan sketch. I'm having to remodel this bathroom in pieces because I need to minimize the impact to my family during the remodel (it's still a functional 1/2 bath until I tear apart the rest of it).

I'll be remodeling the second bathroom sometime next year.

The rule that Terry brought up was change of direction for a trap arm is limited to 135 degrees on a w/c as it drawn the trap arm has only changed direction 90 degrees . what are you concerned with from post 4 sketch not working correctly

 

[wwhitney]

the trap arm has only changed direction 90 degrees . what are you concerned with from post 4 sketch not working correctly

You seem to be counting the combo at the main line as 0 degrees of bend--seems like there's an argument for counting it as 90, or at least as 45 (since it's 45 degrees more than a wye). So I think that's the OP's question with regards to the 135 degrees allowance.

Cheers, Wayne

 

[wwhitney]

the 4" main line is about 3 feet below the slab with a non-load-bearing wall directly above it.

Ah, that does put a different complexion on things. So is the new tub hookup already done?

If so you have experience cutting into the 4" line to add a fitting. Does your current access at the old toilet combo allow you to replace the combo with a wye without much additional excavation?

If it does, sounds like a wye may be worth it, but if not, sounds like the LT90 into the combo would be OK.

Cheers, Wayne

 

[Jeff H Young]

You seem to be counting the combo at the main line as 0 degrees of bend--seems like there's an argument for counting it as 90, or at least as 45 (since it's 45 degrees more than a wye). So I think that's the OP's question with regards to the 135 degrees allowance.

Cheers, Wayne

Yes I was counting that as zero. if it wasn't a trap arm I'd count that as 180 degrees . I'm not 100 percent sure that's correct.

 

[GatorHawk]

Jeff / Wayne,

This is exactly my conundrum... I'm a little confused by the 135 rule, specifically how the fittings "add up". If the wye = 0, then I assume the combo wye = 45. Plus a L.S.90, and I'm at 135 degrees, all is good. However, if the combo wye counts as 90, then there's no way that I can keep it under 180 (with the space I have available). Unfortunately, there's no good way to add a clean out.

 

[wwhitney]

I think you said that the main line is 3' down? I think you have several options to take advantage of that (I'm assuming the combo entry is basically horizontal):

1) In the proposed drawing, rotate the LT90 around the horizontal axis that is up-down the page, ideally 45 degrees. Then the left-right WC drain segment is considered "vertical". Once the drain gets to the WC location, use a 45 to turn up to plumb to connect to the closet flange. Or if it's close, use a 45 degree closet flange. This ought to let you handle moving the WC up to 2.5' to the left of the original location, I think, if the vertical distance is 3'.

2) If you need to move it somewhat more, you could rotate the LT90 up only 30 degrees (or 22.5). Then use a 60 (or 45 plus 22.5) to turn up plumb under the closet flange. I'm not sure if this actual helps with code compliance. I seem to recall some text in the UPC about horizontal lines with extra pitch like that being exempted from cleanout requirements, not sure if the IPC (your code) has anything like that.

3) Another possibility, not sure if this would actually be helpful in reducing blockages, or would just be a possible way around the code language on cleanouts: put the horizontal left-right segment of the drain at a higher elevation than the horizontal up-down-the-page segment. So from the closet flange downstream, you'd hit a closet bend at some intermediate elevation, a horizontal segment to the right, then a quarter bend to turn vertical again, then a LT90 to turn horizontal pointed at the combo, then a horizontal segment to reach the combo.

Cheers, Wayne

 

[Reach4]

How about a wye on the main line, and go straight to the toilet flange (in red on sketch). That would require a skewed hole or slot through the joist.

Or if you have a combo you could put a 45 (in green) on the combo. 45s come with hubs on each end or the "street" version has one hub and one "spigot"(like a pipe). Ah, I see "ST 45" on your sketch.

A combo is a combination of a wye and a 45.

 

[Jeff H Young]

Gatorhawk, give it good grade 1/4 per foot no less . the 90 isn't going to kill you you'll be fine . 2 45s or a wye and a 45 is better but the long sweep will flow without problem . nice cuts and no burrs helps I don't see a problem . other than cracking that slab and digging it out!

 

[GatorHawk]

I hadn't considered the vertical component of this dilemma. I'll have to remeasure my heights and distances, but that could be a solution. I don't want to end up with an angle where the liquids out-pace the solids.

 

[wwhitney]

I don't want to end up with an angle where the liquids out-pace the solids.

I've heard of that theory, but I don't believe I've seen a definitive answer on whether it's real or not.

Cheers, Wayne

 

[Reach4]

I've heard of that theory, but I don't believe I've seen a definitive answer on whether it's real or not.

I initially thought GatorHawk was worried about too much slope, but I decided there was no indication of that.

 

[Jeff H Young]

It worked before , it'll work fine now .