Converting sink drain to tub

We are completely remodeling a bathroom but are trying to use as much as the existing copper DVW piping as possible.

Because the sink doesn't have a ptrap, this will be added and placed in the wall.

Here's a link to a crummy pic:
https://picasaweb.google.com/117159...?authkey=Gv1sRgCKaqkdb0vui8OQ&feat=directlink

The drain in the wall needs to be lowered for the tub. Was going to use a copper/brass (or whatever it is) ptrap from old shower as it is smaller than switching to PVC.

Drain from tub will run on top of floor initially but i'll raise entire tub up a couple of inches so there is enough room for ptrap in the wall. Was going to cut out part of the horizontal wall frame for ptrap.

So plan is also to cut out part of the 2" copper drain/vent and lower that "Y" (sorry, that's the wrong name).

Here's the tricky part. Was planning on unsoldering the vent/drain in that elbow at the bottom and inserting pipe with Y so it is at the correct height for the ptrap.

I know unsoldering something that size is risky. I did practice on some 1 1/2 " copper elbow and it wasn't too hard.

Assuming I don't burn down the house, is this possible or should I try again to convince my wife that using a Fernco is okay and that it won't leak.

hmmm, well. You are aware that your entire bathroom ( tub toilet and lav ) are vented right now through the lav in a wet vented configuration ???

the term you are looking for with the Y is actually a T Wye.

As far as Soldering and unsoldering goes. Make Damn sure you have adequete means of extinguishing a fire should something flash, better safe that sorry... a fire extinguisher is recomended.

use spare drywall and/or Some tin and make a heat sheild so that your torch flame does not touch anything finished or flamablle, drywall will scorch but not burn easilly.

Un soldering things is not that tricky, unless you have water in the line... then its impossiblle.
Grab the pipe with a chain vice grip or something similar before you heat it and then heat up plenty and twist the pipe out.. this takes patience, and you should be carefull that the heat does not radiate and convect up the pipe, igniting or burning something further down the line, Wet rags to isolate the section of pipe, and if there IS water in the pipe an old trick is to stuff WHITE ( must be white ) bread into the line to act as a temporary plug that will disolve later.. This works for potablle also.

An easier idea would be to simply cut the 90 out and then Use a new 90 and a coupler or two, this way you can ensure that the pipe is prepped properly ( cleaned and fluxed ) when you soldier the new fittings in, as you only really get one chance to do soldering Right and pretty.

If you have doubts that you can do this then I advise You to NOT DO IT, this has potential to be a Huge problem if you arnt sure of yourself ( no disrespect intended )

Also, Sink P-traps are better placed where accessiblle, and Then of the union type P trap.... Do NOT put a union type P-trap in a non accessiblle place...

A fernco Done right and torqued properly wouldnt leak on a drain... An MJ would be even Better.


Hope this helps.

I'm not as sure as liquid about it being a wet vent. more of the wall removed and a wider shot would help. i just think you should know that running the drain above the floor is alittle goofy, not to say it wont work and it maybe your best option but if i were you i would at least consult with a plumber in your area. there may be a better way to go.

Thank you for the detailed response.. I really appreciate it.

I'm not sure what "wet vented" means... There is a cast iron toilet closet with a 2" copper vent. Feeding into the toilet closet are two 2" copper drains from two sinks and the shower. Each of those drains has their own separate vent. I have tried to take care to ensure the new tub and shower will also have the same venting, with a trap between the drain and the vent.

I am now worried about that trap. The trap I was going to use is not a union type. It was under the shower and consisted of brass elbows. But I guess that type of trap needs to be directly under the tub drain? The drain for this tub (a deep soak American Standard) can be configured to go either straight down into floor, OR, along the floor. We were going to go with the on the floor configuration (raising the tub up a bit) because the drain at that end of the bathroom is just barely under the subfloor. So to maintain the correct pitch, we would use the along the floor configuration.

The drain would come out of the tub, directed towards the wall, turn left 90 deg, then go through the trap and into the T Wye. There actually could be access to the trap on the other side of the wall as that is currently unfinished "attic" space. When that room is finished, an access panel could be installed. Would that work? And if so, maybe one of those traps with the cleanout plug would be a good idea?

Thank you again for the detailed answer and talking me out of burning down the house.

I did convince my wife that the unsoldering was too hard and that we should just replace that section with PVC, if I can find a fernco to connect 2" copper to 2" PVC.

pro flex couplings go 2'' copper to 2'' pvc. heres the link Proflex Shielded Coupling 2"CI, PL or ST X 1.5" Copper | Fastenal

Use the proflex, not ferncos.
The shielded band holds the joint in alignment.
Copper DWV has a tendency to rot out over time.
I have replaced many rotten DWV trap arms like the one in your wall from the sink. I would run all the pipe in ABS/PVC

Click free your photo. It is out of focus.
Confused a little. Were was the shower?
I see a horizontal trap arm in the wall for a sink going to a 2" stack.
Is the sink going to remain where it is now?
Where is the tub going to be? In same place shower was?
Running a horizontal drain to a p-trap is not a good idea. IMO
It will be very hard to clean.

P-trap should go here on tub drain waste and overflow.

Got to agree with MR David on this one ABS/PVC

Again, thank you all for the comments and advice.

I really want to save money by doing this myself as we just bought this new house and there are other things to spend money on, like a roof, which I won't dream of doing.

Sorry for that lousy pic. I had taken it with iPhone just as a reference when I went to store.

I hope these are better.

First, here is the entire end of the bathroom. Tub will go up against wall and to the left. That's why HVAC vent was moved up.



Here is a close-up of the cast iron toilet drain, which after considering it, we decided NOT to remove it. We will just find a toilet that is narrow enough to sit next to the tub.



Finally here is the area where the tub drain will be. The reason the "on the floor" configuration was chosen was because the drain on that side of the room, which loops around the room counter-clockwise to the toilet drain is just barely under the sub-floor. The tub drain will be at the right side of where the sub-floor has been removed.



I already cut out the previous sink drain and T Wye.

But as it is now obvious to me that using the existing copper DWV drain piping is just not worth it and that switching to PVC is a better idea, we will instead try something else.

The tub drain will be used in a "normal" configuration, with pTrap connected to it (as Mr David's image shows). Will still utilize the existing vent, but rather than connect to that 2" copper drain, will route it back directly to the toilet drain and utilize the existing 1 1/2" inlet, which was used before for the shower.

I'm assuming since the drain for the tub comes with 1.5" pipe, I can use 1.5 inch drain back to that toilet thing (which is 1.5") along with a 2" vent.

I do have to figure out how to attach to the bottom of that vent in some sort of u-turn thing with drain going back in the other direction.

Is that a bit more clear?

Here's a "rough" configuration for the drain piping and vent. Just picked up proper Proflex coupling's at Ferguson's. Nothing is glued at this point so alignment isn't done.

My wife wants that horizontal pipe after the P-trap to go over the floor joist as she wants to make a step on that side... no doubt another disaster in the making.

Not to bad. Nice pictures.
The last picture The bottom 90 should be a long sweep 90 from vertical to horizontal.
You can reduce the drop buy rotating the santee to a 45. You will need to make the notch into floor wider.
use a another 45 fitting on top of the santee to connect back to vent.
Here's a rough sketch

The original 2"copper that goes to the left in floor. drill the floor joist the same way and extend it over to the tub drain then use a tee on it's back where it used to 90 up into wall to connect to the vent.
Your drain will be below the floor and you wont have to raise the tub.
You may have to roll the tee and use a 45 in the branch of the tee to go up into wall to exiting vent

That Is unsupportive and unhelpfull Another plumber.


Mr david on the other hand, gives solid advice..

Now to the original poster: a Union style p-trap Must be accesiblle because there is chance that over time It Could work its way free and leak.

From the scale of Questions you ask, I would suggest getting a plumber.

and Thirdly, A drain ( by canadian code anyways ) cannot change direction by more than 135 degrees before it meets its vent as the change of direction slows the water and will result in clogging.

Thanks for all the helpful comments and advice.

I like turning that T Wye 45 degrees.

I'm most concerned about the accessibility of the trap and will have to give that some thought.

Right now, if the drain is installed so its exactly vertical, the horizonal section of pipe from the trap to the T Wye will be almost level for about 12 inches. Doesn't that need some downward pitch?

Nice job so far. Mr. David has the helm on this one. I will just quietly observe. My codes have some subtle differences that would just create confusion.
Liquid: 135 degrees or 45 degrees?

Caduceus said:

My codes have some subtle differences that would just create confusion

Click to expand...

I do suspect that codes for Allegheny County, PA are more similar to those here in Montgomery County, MD than they are to San Diego or Alberta.

But as long as we have no leaks or clogs I'll consider it a success as I wasn't planning on inviting any inspectors into my house.

Mr_David said:

The original 2"copper that goes to the left in floor. drill the floor joist the same way and extend it over to the tub drain then use a tee on it's back where it used to 90 up into wall to connect to the vent.
Your drain will be below the floor and you wont have to raise the tub.
You may have to roll the tee and use a 45 in the branch of the tee to go up into wall to exiting vent

Click to expand...

Guess I'm a bit slow as I didn't exactly understand what you were suggesting until just now.

It's ridiculously simple! though rather than use that 2" copper (which has 40 years worth of hair and who knows what in it... which actually caught fire inside the pipe when I was trying to unsolder... ) we were going to use 1.5 PVC, make wide sweeping 90 turn to left and over to cast iron toilet closet where the shower drain used to connect.

Have a nice 2" drop over 6 feet.

But the trap will be in a completely unaccessible location... right next to exterior wall of house... in the two foot overhang of the first floor and right over brick wall on one side... close to another brick wall for fireplace.

I'm thinking that might not be a good idea?

Seems kinda silly to raise the tub 6 inches just for that.

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I just posted this at 9:25 PM EDT. Why does it say 7:02 AM? I know I have the time zone correctly set to EDT. I just checked it.

AJay said:

Right now, if the drain is installed so its exactly vertical, the horizonal section of pipe from the trap to the T Wye will be almost level for about 12 inches. Doesn't that need some downward pitch?

Click to expand...

Code in my area is at least 1/4" of fall for every 1' of run. While you can possibly get away with less, you are more likely to have problems with clogs.

Yeah, AJay, I figured you wouldn't, but your DIY project looks a better than most that I've seen on the internet. Heck, it looks better than many I've seen installed by plumbers!
It would be nice to see the rough-in before you close everything up.

Caduceus said:

Nice job so far. Mr. David has the helm on this one. I will just quietly observe. My codes have some subtle differences that would just create confusion.
Liquid: 135 degrees or 45 degrees?

Click to expand...

135 degrees or 3 45 degree changes in direction of the trap arm for a lav or tub etc. 225 degrees total change for a W.C. ( this includes the Vertical to horizontal 90 ) So basically 135 degrees for any horizontal pipe, The exception being a circuit venter fixture where the trunk line cannot change more that 45 degrees without the addition of a vent ( offests of this nature are typically, if possiblle done with 2, 22.5 degree fittings.