Shower drain not level, taking over from plumber

[smred]

First timer here,

We're remodeling the kids' bathroom. New shower going in. Plumber did all the rough plumbing so it's to code and done right. However, he wasn't planning on putting in a pre-slope and with all I've read/watched I know that's not right. My husband and carpenter think since we're not going to be here more than 6 more years that we should just let the plumber do his thing. I disagree.

So, I was planning on building the shower pan. I would do:
subfloor
tar paper
metal lath
mud pre-slope
oatey liner
mortar
tile (sliced pebble)

My problem is that the plumber hasn't glued the drain piece to the underlying pic pipe. If I seat the drain into the pipe all the way, it's not level. I could glue it so that it's level, or I can push it into place as there is some play to the pipe underneath, but there are no screw holes to fasten it to the plywood.

So, questions are:
1. How high should the bottom of the drain flange sit above the plywood?
2. Does the drain need to be fastened to the plywood or does it just sit on top?
3. Should I glue the drain to the pipe so that the top of it is level or should it sit all the way into the pipe (and if it's all the way in how would I get it level?)

See pics below. First

Lastly, since I've never built a pan before, and there is definitely a risk to my making a mistake as well (which my husband thinks is more of a problem than letting the plumber put it in his way) what do you recommend?

Thanks!

[cx]

Welcome, SusanMary.

You should tell Mr. SusanMary that, as usual, you are correct in this.

Originally Posted by SusanMary

Plumber did all the rough plumbing so it's to code and done right. However, he wasn't planning on putting in a pre-slope

Bit of a contradiction there, I'm afraid. He cannot install the shower pan liner without a pre-slope and still be meeting plumbing code requirements. Not at all uncommon, though, unfortunately, but don't allow that to happen. And don't be shy about telling the plumber he's wrong about laying the liner flat on the subfloor. He's supposed to be the "knowledgeable professional" in that situation and should certainly know that his plumbing (the liner) must be properly sloped to drain.

If you set that Oatey drain on the four little "feet" it has on the bottom, you'll usually be close to the necessary minimum 3/4" thickness for the thinnest portion of your pre-slope. There is no such minimum in the plumbing code, but the ceramic tile industry never specifies deck mud thinner than that and the pre-slope would then be installed as you described. You'd probably need to install a second layer of plywood subflooring so as to provide a smaller hole around your drain riser to make that work. Or remove and replace the patch of plywood subfloor it appears you have. And if the plumber did that patchwork, it's likely you would want to install better blocking around the perimeter of the patch.

If your drain riser is not plumb, make it so. Your plumber should have done that. You'll want to fasten the riser or the P-trap to your framing such that it remains fixed in that plumb orientation if at all possible. While it's possible to correct a bit of out-of-level when gluing the drain to the riser, you want to do as little of that as possible. Better to have a plumb riser and glue the drain on square.

My opinion; worth price charged.

[smred]

Hey CX,

Thanks for confirming my hunch.

In credit to the plumber, he did ask my carpenter to put in another piece of 5/8" plywood to beef up the subfloor. Plumber was planning on doing that and having to raise the drain to allow for the extra layer of plywood which I'm inclined to let him. I'll ask him to secure the p-trap to the joist so that the drain is level and set the drain so that I have the 3/4" depth for the pre-slope.

Who knows, he may be thrilled not to have to do the work! I just have to make sure I don't make a mistake or all the guys around here will say they were right :-).

Just wish I didn't have to buy a whole roll of tar paper and a huge sheet of metal lath just for this one shower pan!

[speed51133]

search craigslist or ebay for "roofing felt" and "tar paper".

you can find scraps or by the foot perhaps. I just found multiple sellers in my area selling partial rolls on craigslist for less than 10 bucks.

[cx]

SusanMary, the roofing felt serves no purpose other than separating the subfloor from the mud so the plywood doesn't suck the moisture out of your deck mud. Some plastic garbage bags, an old shower curtain, other polyethylene sheeting, or similar will serve the purpose just as well.

If you're paying this plumber he should be the one to install the pre-slope and the shower receptor liner, anyway. And he should be doing it correctly. There is no requirement in the plumbing code indicating just how the pre-slope is to be constructed, but that liner must slope a minimum of 1/4" per horizontal foot from the furthest corner of the shower footprint.

My opinion; worth price charged.

[smred]

So, I've checked the MA plumbing code and all I can find about the shower pan is:

Shower Floors or Receptors.
1. Floors or receptors under shower compartments shall be laid on or be supported by a smooth and structurally sound base.
2. Floors under shower compartments, other than those laid directly on the ground surface or where prefabricated shower base receptors have been provided, shall be lined and made watertight by the provision of suitable shower pans of durable Product- accepted materials.
3. Shower pans shall turn up on all sides at least above the finished threshold level.
4. Shower pans shall be securely fastened to the waste outlet at the seepage entrance making a watertight joint between the pan and the outlet.
5. Floor surfaces shall be constructed of smooth, non-corrosive, nonabsorbent, and waterproof materials.

Doesn't specifically require a pre-slope. Doesn't mean I've changed my mind, but I will bet you a craft IPA that my plumber won't put one in. Can anyone show me MA plumbing code requiring a pre-slope?

[ss3964spd]

Can't speak to what's code in Ma or your county in MA, and the plumber may see no need for a pre slope, but you're the paying customer, SusanMary and if you ask him to install one he should accommodate your request I think.

Also, when the time does come for the liner, you'll want to notch those wall studs to accommodate the thickness of the liner where it folds in the corners. Neglecting to do so will result in whatever type of wall board you decide to use bulging out at the bottom. Ideally, all the studs would be notched to a depth which matches the thickness of the liner, the blocking between the studs set back by the same about, and the studs in the corners notched deeper than the rest to accommodate the folds.

[speed51133]

It appears as though the wonderful state of MA doesn't require a pre-slope, at least based on 30 min of searching codes and various forums. They also have their OWN plumbing code and do not follow any of the other national/international codes.

[smred]

Thanks Mike,

And therein lies the rub. Plumber says he's installed hundreds of pans without liners and the only time he's had callback is when someone punctured the liner installing the cement board.

So, I'm either back to doing it myself or hiring another plumber to put it in. Leaning towards doing it myself. Already successfully put in the heat mat and tiled the floor, so I think I can do it.

If I add the 1/2" layer of plywood, the drain pipe will be too low. My question is, after setting down the new layer of plywood and cutting out the 3 1/2" hole for the drain, it sounds like the pipe should be cut so that when installed the feet on the drain should sit on the top of the new layer of plywood - yes?

If so, how do I add height to the current drain pipe? I'm thinking I would cut it down, and a coupling (size?) and add new 2" pvc pipe? How do you cut the pipe from the inside? My other thought is to have the plumber do that part when he's installing the tub faucet in 3 days. Then I would just tell him to set the drain on top of the plywood - yes?

More questions later as I get to the next step. Thanks!!!

[jlbos83]

https://www.homedepot.com/p/Husky-In...E&gclsrc=aw.ds

Shove a sock or something down the pipe, so that when the cutter falls out the your drill, you can fetch it.

[Davy]

Jeff is talking from experience. I've had it happen. Luckily it stayed in the P-trap and my telescoping magnet picked it up.

[smred]

As for notching the studs....

I didn't set the 2x6's back at all, so I can notch just where the folds are (and stick as much of it as possible back through the cracks between the studs and the blocks), or take 'em out and move the blocks back by 4ml and notch the studs (which seems like a whole bunch of work).

Or, I could shim the lower portion of the studs and cover with 1/4" cement board, making it flush with the 1/2" that's on the upper portion and then I'd have 1/4" to play with between the studs below the shimmed portion.


Thoughts?

[Tool Guy - Kg]

Either move the blocks back and notch the studs so the cement board remains flat...or fur out the studs above the liner all the way up so the cement board remains flat.

Originally Posted by smred

Or, I could shim the lower portion of the studs and cover with 1/4" cement board, making it flush with the 1/2" that's on the upper portion and then I'd have 1/4" to play with between the studs below the shimmed portion.

Are you saying that you already have 1/2” cement board installed on the upper portion of this shower? If so, why not remove the 1/2” cement board above so the you can run furring strips from just above the liner all the way up and use 1/2” cement board everywhere? If I’m not understanding correctly, please clarify.

[ss3964spd]

Originally Posted by SusanMary

Or, I could shim the lower portion of the studs and cover with 1/4" cement board, making it flush with the 1/2" that's on the upper portion and then I'd have 1/4" to play with between the studs below the shimmed portion.

Am having a bit of difficulty following, SusanMary, but I'm only on my first cup of coffee.

I do see one corner into which you can possibly tuck the liner in between two studs that make up a corner, and can also see another corner which it doesn't appear you'll be able to. Those folds end up being pretty thick.

Yeah, moving the blocking back and notching is a lot of work, but I feel like you'll spend as much time and effort trying to make something else work, and it may not end up working as well as you want. Just my opinion.

[smred]

Yeah, that was a bit confusing. I was thinking if I used 1/4" board below the 1/2" board already on the walls above, but shimmed the 1/4" at the studs I'd have 1/4" extra space behind the board below the lowest screw to accommodate the liner. But, since that isn't making sense I'll move the blocks back and notch the studs (as best I can). Is it primarily the folds that are the problem, or does 4ml really bow the board out enough to mess up the tile?