space issue converting from CI to ABS under toilet

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tireguy

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I read the following thread and have a similar problem that I could use some advice on:

https://terrylove.com/forums/showthread.php?t=14622&highlight=toilet

I am remodeling a house and it has cast iron sewer pipe & stack. I need to move the toilet about 18" along the wall, and a little closer (to the standard 12" distance) t the wall. I want to keep the CI stack as-is since it is in good shape and more desirable for noise. The existing toilet 90-deg elbow came right out of a tee hub in the stack. It had an inlet on each side; the sink was on one side and the tub on the other.

I have already cleanly removed the toilet ell from the hub (drilled out the lead, scored the CI ell with a grinder, then broke apart with a sledge hammer). Unlike the method described in the above link, I could not snap off the CI and use a neoprene coupling due to space issues and the need to include a cross between the CI hub and the toilet ell. (I need 12" distance of flange from wall and there is a floor joist running parallel to the wall, but the pipes should clear (barely)).

I plan to come out of the hub with a short section of 3" ABS using a neoprene CI hub adapter ("donut"), then immediately use a 3x2x3x2 cross (the 2" on each side going to the sink and tub). Using a regular street ell I have just enough room to turn 90 deg to run the 18" distance parallel to the wall (a long sweep takes too much room and interferes with the floor joist). From there I turn 90 deg up through the floor and into the toilet flange.

My problem is the CI hub is too close to the floor above to run my pipe and turn up and have the flange rest on the floor - even when accounting for sub-floor, floor, backer board, and tile thicknesses and using a regular street ell. The hub to floor clearance is 1/2". That makes the center of the hub 3-1/2" from bottom of floor. Add 3/4" sub-floor, 1/2" floor, 3/8" tile backer board, and 1/4" tile and the flange will be a little too high.

Here are my questions:

1) Is there some special ABS toilet ell they make to give me a sharper turn up through the floor without causing toilet back-ups? Or can I use a close ell here without causing problems?

2) Is there any problem using a cross next to the stack for my sink and tub?

3) is using a "donut" OK with code (I am in NE Ohio) in a horizontal run? If not, do they make hub adaptors that can be leaded in the hub using lead wool or floss with oakum?

4) do I need to vent my sink and/or tub if the sink is 3ft away and the tub is 5ft away from the stack if I am using 2" pipe for these?

5) If I need to, or should, vent the tub and sink, is it OK to use a saddle clamp into the CI above the fixture drain heights? Or is there another way to tie into existing CI?

Your expert advice is appreciated. This stumps me and progress is being held up awaiting a solution.
 
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Leejosepho

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tireguy said:
Is there some special ABS toilet ell they make to give me a sharper turn up through the floor without causing toilet back-ups? Or can I use a close ell here without causing problems?

Not being a professional who must adhere to code in order to have an income, I would likely use the close ell if there is no other reasonable option available.

tireguy said:
Is there any problem using a cross next to the stack for my sink and tub?

Not as far as I know.

tireguy said:
Is using a "donut" OK with code (I am in NE Ohio) in a horizontal run? If not, do they make hub adaptors that can be leaded in the hub using lead wool or floss with oakum?

I would guess there is a better way to do that, but maybe not.

tireguy said:
Do I need to vent my sink and/or tub if the sink is 3ft away and the tub is 5ft away from the stack if I am using 2" pipe for these?

Simply using 2" pipe is the way I would do that in my own house.

tireguy said:
If I need to, or should, vent the tub and sink, is it OK to use a saddle clamp into the CI above the fixture drain heights?

I recently learned from the real plumbers here that a saddle is never a good idea.
 

Master Plumber Mark

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doughnuts are mean

I have never had much luck with doughnuts....

Unless you can grease that doughnut real well
and be able to literally beat and pound that abs plastic nipple into the socket.....you are in for trouble.

you can buy a trap street elbow that might give you another inch...

I have had to in the past actually cut a 1/2 inch off the
male end of a street ell with a hack saw to get the flange to sit flush on the floor when it was glued...

I also have had to cut the flange down a half inch
too...... whatever it took to get them flush....as long as you
still have at least half the joint left it will work




the first hurdle you need to get past is the 3 inch nipple
into the doughnut...

have fun
 

Jadnashua

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From what I can gather, the only thing standard about CI is the inside diameter; the hubs vary in size by brand and time of manufacture. Most stores only carry one, maybe two sizes of dognuts for a given size of pipe. The manufacturer makes a huge variety. To get the right one, you may need to order it. This is my impression of why some say they work great, and others say they are nearly impossible to install or leak. If you get the correct size, it isn't too bad, but too loose (leaks) or too tight (nearly impossible to install), and you'll swear they couldn't possibly work. In my last at home project, the "standard" size rattled around in the hub, and the oversized one they had still didn't seal...I ended up snapping the whole thing out and replacing with pvc. Had they had the "right" one in stock, it would have been quick and easy.
 

SRdenny

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How about a picture of the cast iron fitting? How about leading in a 4" no hub cast iron closet bend? The 3-1/8" you'll have (5-3/8"-2-1/4") is more then enough for a closet ring. All you'll need is some lead, oakum, irons, running rope,ladle, torch....aaaannnnd a plumber who knows how to use them.
 
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