How to Level a PVC Shower Drain?

Hello Everyone. Learned of this site through the John Bridge ceramic tile forum. Some quick background to my question:

I'm finishing out a second floor master bath shower with 3/4" plywood sub-floor and 2" PVC drain piping. To accommodate the type of shower drain/system I want to use (Kerdi by Schluter) I first needed to remove an existing copper pan and brass drain by using an inside pipe cutter on the original PVC riser. After removing the pan/drain I noticed that remaining riser was not completely level. I figured I might have a little "wiggle room" to bring things back to level as I glued a coupling and riser extension piece onto the cut riser, but either my lack of skill or the design of PVC coupling didn't allow me any "wiggle room" to get it level.

So my question now is how to level the riser (if possible) before installing the drain. One suggestion made was to use a heat gun very carefully to soften the PVC and position it correctly. It's also possible I could use a strap of some sort to put pressure on the riser, "pull" it level, then attach the strap to a joist to hold it, but stressing the PVC like that didn't seem like a good idea.

Are there any other suggestions out there? If the heat gun is the way to go, where might I find (rent?) one, and could anyone give some more advice on using it?

Thanks in advance for your help!

Where does this 2" pipe go to, when shower water drains? How much wiggle room do you have all in all? If there is an elbow right under the shower drain, have you seen the level-ness of the pipe running underneath your bathroom? It'll most likely be pitched at about 1/4" per running foot. Since that is itself not a level start, it is normal to see some of tha impact on the riser. How much ? In your case.

David

Good Questions

Genie/Grumpy (hmmm...is there a Terry Love Plumbing version of the 7 dwarfs?? ),

Thanks a lot for responding! Good questions; sorry I wasn't clear. I'm not at the house now but will be there Friday afternoon and will answer your questions accurately/definitively. The initial work I mentioned was done about a year ago (sometimes "life" intervenes in projects) so I'm working from memory at the moment.

Until Friday, here is what I THINK the answers are:

- the "riser" (vertical 2" pipe) comes up from the trap and connects to the drain
- the trap then connects to a horizontal pipe, running between joists, sloping appropriately away from the shower to a waste stack or pipe
- yes, I incorrectly spoke of "leveling" the vertical riser; I should have referred to getting it "plumb" (I had "level" in my head because I put a torpedo level across the top of the new riser)
- as for exactly how much out of plumb it is, I'll have to check Friday and let you know.

Attached is a picture of the original riser, after I removed the old pan and drain. Unfortunately it is a little fuzzy and may not confirm that the riser is attached directly to the trap. All I did from the point of that picture was use an inside cutter to cut off the riser and remove the old threaded drain connection; then glue a coupling and additional riser piece to give me the appropriate riser height for the new Kerdi drain.

Hope this is clear...pls. ask if not! I will be back Friday to confirm/disconfirm what I said above and send another pic. If you have any instructions on how to gauge/communicate the "out-of-plumbness" pls. let me know (a torpedo level and picture?).

Really appreciate your help....Derek

OK I fess up to being "plumbing dumb"...

Thanks Grumpy. I have to admit, I wasn't sure at first what you were talking about but I think the "street" and regular 22's are elbow joints. I will confirm that and will also write back to answer Genie's question about how "out-of-plumb" the whole thing is anyway.

Will be back to you Friday afternoon/evening...

Thx for the help....Derek

A Few More Pictures...

Hello Genie/Grumpy & All:

I'm now at the project house and most everything I said previously was correct with one exception...after cutting off the original riser/drain attachment I only glued a coupling back on to the riser stem. I still need to glue in the next riser section that the Kerdi drain will slip over.

Here are some additional pics of the riser stem and coupling, showing as best I can the degree of out-of-plumb I'm dealing with. The wide flange of the Kerdi drain will be imbedded in a mud bed, and I guess I could just push it in flush all around even tho' it is out of plumb, but I was hoping to get it plumb so the drain flange would then be level with the rest of the floor.

If there was some "wiggle room" in gluing the final riser piece into the coupling, I may be able to get it close to plumb. However, when I glued the coupling on to the original riser stem I was not able to "wiggle" it...the pieces seemed to fit together pretty tightly.

Is there a technique for achieving some wiggle room and adjusting plumb as you are gluing vertical pieces? If so this would be a great help. If not, Grumpy, would you still recommend your last solution (cutting it out and using 22's)?

I know that this is a stupid little problem in the greater world of plumbing, but it has a novice like me stuck at the moment.

Thanks in advance for your help!

Derek

simple answer

The easiest/quickest way is to use plumbers tape and make it level that way.
The more professional approach is to say forget it and pop a beer.
CHEERS!

DerekW said:

-Hope this is clear...pls. ask if not! I will be back Friday to confirm/disconfirm what I said above and send another pic. If you have any instructions on how to gauge/communicate the "out-of-plumbness" pls. let me know (a torpedo level and picture?).

Click to expand...

HINT:
Sit the level FLAT on the top of the coupling...
It will read on all bubbles at once and allow you to take reading both ways - that way you can see just how out of plumb it is in one glance...

I would probably cut the trap out and re-do it...(new coupling and trap)
When gluing in the new trap, use the flat level trick to get it perfectly plumb...
(sit it on the hub of the trap as you turn the trap and the glue dries...)

Good Ideas...

Thanks all,

Grumpy, I glued the coupling because I don't even know how to spell "pipe" (duh). Do you mean never glue coupling or 22 joints, or only until you've marked them for plumb? As I said... can't spell "pipe"!

Matt/Markts...thanks for the ideas!

Will get a couple 22's, consider all advice, stare at it....and probably be back with a final question or 2.

Thanks so much.....Derek

Hey Derek,
yes its real easy, cut that riser down and dry fit a 22 onto the existing riser coming out of the P trap. cut yourself
a peice of pipe ( what we call a "close" wich will be no longer than 2 inches. and stick it in the other end of the 22 .now on that end of the pipe stick your other 22 on and spin it until your level reads LEVEL! Now mark the side of all pipe and fittings with a pen or lumber crayon like a line going down the pipe and fittings. Now pull all those dry fitted peices apart and start gluing them together making sure the lines you made on the fittings and pipes all line up again. and there ya go its done. its realy super easy. dont think so hard on it just do it. if you want a real pain in the butt way to do it -dare I say- you can always cut the riser below the coupling add a new coupling and the final second half of the riser and
shave the high end of the top of the drain pipe and make it level.
now this..... depending on the grade of that angle will either work out OK or screw you over as it will diminish the amount of pipe that will be glued into the inside hub of your male shower drain adapter.

DerekW said:

Thanks all,

Grumpy, I glued the coupling because I don't even know how to spell "pipe" (duh). Do you mean never glue coupling or 22 joints, or only until you've marked them for plumb? As I said... can't spell "pipe"!

Click to expand...

Derek...GLUE them when you have the riser both plumb, and centered on the shower drain.
Also...rather than scrolling back to what I originally posted, MattAlexander (above) literally typed the same thing almost verbatum. (he might do this fer a livin')

Cut out the p-trap and start over.

Thanks All! Have been away from internet access for a couple days...

I found a couple regular 22's but am having trouble finding the street 22's at either of the big box stores. May have to try a plumbing supply house tomorrow or Thurs. But I think I get the concept and agree it doesn't sound hard.

Also, the advice to cut the whole p-trap out and start over makes sense too, but I may try the minor surgery before going with the major.

Be back soon!

(Grumpy...they say imitation is the greatest form of flattery!)

Just a Couple More Questions....

Grumpy/All, thanks for the advice. It took a little while to get back to the project...

I have the 2 street 22's and understand what you are saying about working them around and marking them to get a plumb riser. Just a couple more questions:

1) is it OK to shim the p-trap assembly up about 5/8" and put a little stress on it? (the "flexibility" is there to do it). Reason I ask is that with the Kerdi drain, I need the top of the final riser to be approx. 1 1/2" below the sub-floor. Unfortunately I can't just put the 2 - 22's into the coupling I already glued onto the riser stem...that would be too high (see previous pics if that helps). The other way to go is to cut the coupling off, just at the bottom of it, but putting the 2 - 22's on the section of riser that's left would be about 5/8" too low. I can solve that by shimming the p-trap up a bit if putting a little stress on it is OK.

2) Assuming it's OK to shim the p-trap, and I cut the coupling off, I'll have about a 1 1/4" section of 2" riser coming out of the trap; then the 2 22's over that, which will leave the "male" end of a 22 for the "riser" that the Kerdi drain will fit over. Is there any problem doing this? It wouldn't seem so since the end of the 22 is the same outer dimension as 2" pipe, but I thought I'd ask.

Thanks in advance for your help again. You folks are great!

Derek

If the existing p-trap was glued on crooked, I would just cut it out, and glue a new one on right.

Right = straight and vertical.

Thanks Terry,

I'm sure that's the proper fix. I was going through the other maneuvers Grumpy and Matt suggested because to cut the whole p-trap out I would have to get access by cutting out a much larger section of the shower subfloor, or come up from beneath and cut out a section of the first floor ceiling below.

Do you think shimming the p-trap a bit and using the 2 street 22's is workable (and not harmful!), even though it is not the ideal solution?

Really appreciate your help......Derek

One More Thought...

As I was shimming the p-trap up to get it higher I noticed that the shimming also brought it very near plumb in one direction ("front to back"). This means that the existing assemblage is now only out of plumb in one direction ("side to side", as shown in attached pics #3 and #5, in my post #7).

Sooo.... it might be possible to just glue another riser piece of the right height into the existing coupling....IF I was able to tilt it a bit to one side as I was gluing it in to get it plumb.

This is kinda where I started. I was told that this was possible when gluing PVC, but I tried it once and the pieces sure didn't want to go together any way but "straight in".

Is there a way of gaining a little wiggle room when gluing a piece of 2" PVC into a coupling, so as to bring it plumb if the coupling itself is not plumb??

Sorry again for such basic questions but that's where I'm at!

Thanks......Derek

You will have a bit of "wiggle" room but not much...
Putting stress on a plumbing joint (be it plastic of cast iron or anything else) is NOT a good idea...
They tend to break later at much more cost...
Could you not use a shielded coupling on the riser and plumb it that way - you can get a lot more "wiggle" in a banded coupling than a glue joint...