A question of fittings...

[TonyBagadonutz]

What is the differnce between these fittings (when used for waste lines)?

3 Inch DOUBLE, FIXTURE FITTING, HUB

4 Inch TEE, DOUBLE, SANITARY, HUB



The reason I ask, is that I cannot locate a 4" double fixture fitting at the LASCO site ~ I have to question if the part is even made? The supply houses in my town use NIBCO fittings ~ the fittings in the pictures are LASCO...and are not even sold in NJ.

The NIBCO (their products are sold in NJ) site offers a fitting similar to the fitting show below:

4 Inch WYE, DOUBLE, COMBO & 1/8 BEND, HUB


Would this fitting be allowed for waste lines?
...or should I just put the 4" double Sanitee in?

I guess what I am really asking is "What can I do if right fitting is not available/made in my state?"

Would it be possible to reduce the stack at the 3" fitting if that is my only option? Above the 3" fitting will be 1 waste line for the pedistal sink and sink venting, 2" venting to pick lower fixtures, shower venting, out roof.

Something like this:

 

[RioHyde]

Double fixture fitting.​

The double combo fitting is what is used here for water closets and urinals. We cannot use the cross for these fixtures due to the possibility of the waste rushing past the drop and into the other fixture drain. Every plumbing supply house I've been to carries the double combo (as well as the cross). You shouldnt have any trouble with that fitting.

 

[Sponsor]

 

[TonyBagadonutz]

Double fixture fitting​

I went to 2 different supply houses today...showed a counterman at each location a print out of the double fixture fitting..

Double Sanitary Tee​

​

they both produced the 4 Inch TEE, DOUBLE, SANITARY, HUB.

I even checked on **** in case a contractor had overstock they were tryng to dump.

This one fitting is holding up the entire bth project - I can't put in a joist, floor, chase framing for stack, tub waste/vent, sink waste/vent etc. I am officially 1 week past schedule on the plumbing rough which will translate into at least 2 weeks past on the finish.

This is driving me batty.

(****= huge online auction site...I guess it IS a four letter word...LOL)


Would something like this be legal?

The 4" stack goes to a 4" Sanitee. Up connects to sink and additional venting. Out goes to a Tee (or wye?) to pick up toilet and shower.

 

[Terry]

TonyBagadonutz,

Could you use a santee off of the stack for the toilet,
and then below that have a wye and a 45 pointing upward,

from there you could put a santee pointed toward the shower with a vent off of the top that would revent into the vent stack.

I almost never use a 3" or 4" double fixture fitting.
It's easier to use a combination of fittings and to tie the vents back together.

I do use a few 2x1.5x1.5x1.5 double fixture fittings on double lavs and on some kitchens.

 

[TonyBagadonutz]

Terry,
you mean something like this?

To add the venting off the lower wye would be adding more challange to this situation. I can vent the shower immediatley after the the drain exits the tub area (after the trap, of course).

The main stack is brought up through a wet wall on the first wall. This wet wall does not exist on the second floor - the main stack and supply lines are brought up into a boxed out chase that protrudes off the side wall of the second floor bath. The walls do NOT line up between 1st and 2nd flrs in any direction. In the drawing below, you can see what I mean.

The heavy black lines represent the 2nd flr wall layout, while the pink lines depict the 1st flr walls. There is also a 2x6 stud in the wet wall directly to the right of the main stack - to wye out of the stack on the 1st flr would involve notching this stud. One more log on the fire is a 2x8 floor joist that runs parallel to the wet wall that is (as you probably guessed) at just about 12" OC (after 2nd floors are rocked and wainscoted)...the toilet gets a 12" rough. I can (and will) rearrange these joists/studs as needed.

Correct me if I am wrong, but I think the easiest (maybe not legal) solution is put the double fixture fitting (or the double combo with 45°) so the outlets are slightly off-center to the wet wall below. I need to drop down some vent lines for the future rehab of 1st floor bath ~ 1 2" vent line on either side of the existing stack and parallel to the stack so these lines remain in the wet wall.

 

[hj]

fitting

You cannot use the sanitary cross except for the vent connection. The double fixture fitting only goes up to 3". If you use the double combo, then each of the lines connecting to the side branches has to have its own vent, separate from the main vertical pipe.

 

[TonyBagadonutz]

The double fixture fitting only goes up to 3".

Great...not what I wanted to hear, but thanks....I might just have to reduce that trap arm(is that proper terminology?) to 3" because I may need an offset closet flange(joist is roughly 12" OC) - the guys at the supply house said there is no 4" offset flange.

If you use the double combo, then each of the lines connecting to the side branches has to have its own vent, separate from the main vertical pipe.

If I use the double combo...layout is: closet flange, closet bend, 45°(possibly 22.5°) , double combo...where does the vent fall into place? (The shower vent is no problem). The stack to toilet OC measurement is about 20" - 24", the toilet is 12" OC from back wall. With these dimensions in mind, would wet venting this one fixture be possibile/allowed?

 

[hj]

fitting

The vent would have to be connected between the closet bend and the double combo which could rquire an "interesting" routing to fit it in. A plumber looking at your installation might "throw" your whole design away and create an entirely new one. I can think of many ways that I would do it, but would have to be there to see the actual physical parameters to see if any would work. Can you install the 3" doulble fixture fitting next to the 4" and create a completely new layout independent of the existing 4" stack?

 

[TonyBagadonutz]

A plumber looking at your installation might "throw" your whole design away and create an entirely new one.

I am not a plumber - really I'm not - but I have been pondering that concept of tossing my plan A/B/+C for a plan D .

I can think of many ways that I would do it, but would have to be there to see the actual physical parameters to see if any would work.

That's because you have a clue ...I hesitate asking for someone to just "give" me a proper layout ~ sure it gets the job done, but what will I have learned (learnt?). I also think it's kind of arrogant to just say "I tried , I failed, you do it". I haven't thrown the towel in yet, but if I do..I will humbly ask for much more help than just reviewing my "plans"...and maybe some sympathetic soul will oblige me.

Can you install the 3" doulble fixture fitting next to the 4" and create a completely new layout independent of the existing 4" stack?

I was thinking along those lines.
I will build an other proposed stack.





Have I said "Thanks " lately?
Thank you (just in case I forgot)