Basement Shower on Slab Trap Help

[mntnresq]

Hi,

My four year old house was roughed for a basement bath, but clearly they had a tub in mind, and set the riser from the trap basically right against the foundation wall (Pic 1). I am installing a standalone 60" x 34" shower, and need to move the drain location away from the wall some.

After much searching I found a shower pan with the drain centered only 4.5" off the end (it's a faux linear drain) to give me the best chance of making this work without major surgery, but now that I'm getting into it, I'm still not sure it will work. The drain location is the template I made (pic 2).

My first thought was to try to get the riser to the right location by just angling it back with a couple 45's, (pic 3) but I can't get far enough back without making it too tall (Above the slab). So that didn't work.

The other option is to replace the trap, but the problem is there basically isn't enough room to push the riser location far enough back without setting the trap up basically 180 on itself (pic 4). From other reading on the forum, it sounds like this is acceptable, but I'm still concerned that it may not drain well, forcing the water to basically double back. Even if this would be ok, I would also have to extend the horizontal line by about 1.5 - 2" to get it in the right spot, which means a union in the middle of a 7" piece, which I also don't like.

I can't just cut the horizontal line back further (basically push the trap under the slab) either, as there is only about 5" before it hits the wye feeding into the lateral to the main. You can see the edge of the wye in pic 4.

The only other option (which I am obviously hoping to avoid) would be to cut or hammer the slab back to expose the lateral, cut out the existing wye, and move it down to where the angle of the inlet would intersect where I need the trap to be.

I plan to use an Oatey 420994 Caulk-less flange on the pan- it just seems like the simplest solution to get the pan set. My plan was to leave the riser a bit long, leave the gasket out of the flange, set the pan, then trim the riser to the right height, since it's hard to know how much the pan will bed into the thinset. Then I can put the gasket on, tighten the inner nut, and it should be perfect.

So, I guess my questions are:
1. Is it really ok to orient the trap like that (and would you)
2. Is the short run with a union any concern?
3. Any other ideas/options I haven't thought of?
4. On my flange plan- Does that sound reasonable, and any good/bad experience with them or similar ones? I've read suggestions to use dish soap on the gasket so they slide on easier?




Thanks for any help or suggestions.

 

[Breplum]

Use the brass version of that Oatey drain. The whole thing is much more sturdy. On the plastic ones, the bottom nut has a tendency to pop off the threads.
You can definitely swing the trap "on itself". 2 inch No hub coupling (not a union) properly tightened with a t-torquer wrench is ok to use (not a union).
Use a proper drain wrench too:
Oatey 42239 Brass and Plastic No-Calk Shower Drain Wrench, Stainless Steel
You are on the right track, but you might find a solo plumber in the area to get this done right without having to buy a few tools.

 

[Sponsor]

 

[Sylvan]

Have you thought of having a plumber make a lead pan to fit in the space and then they can set the drain right where it is??

Use a cast iron riser connected to the PVC with a no hub coupling and buy either a Jones spec or JR Smith cast iron Quick set shower drain and the plumber can make a caulked joint or use the Quick set where the bolts are tightened

 

[Reach4]

1. Yes.

2. Yes -- no inaccessible unions I think.

3. shower base in concrete

clever position marking.

 

[mntnresq]

1. Yes.

2. Yes -- no inaccessible unions I think.

3. shower base in concrete

clever position marking.

Thanks for the tip on locating the drain. That's pretty much exactly what I did though I marked and cut out the hole in the pan, I'll do it again with just the pipe size.

And, I'm using the wrong terminology- I didn't mean a screw-together union, I meant just a solvent weld coupling.

 

[mntnresq]

Have you thought of having a plumber make a lead pan to fit in the space and then they can set the drain right where it is??

Use a cast iron riser connected to the PVC with a no hub coupling and buy either a Jones spec or JR Smith cast iron Quick set shower drain and the plumber can make a caulked joint or use the Quick set where the bolts are tightened

That wouldn't have worked, for a couple reasons. One, I already bought the pan (special order- took FIVE months to get it, it's not going back at this point), and the original drain had to be moved regardless. It was touching the foundation wall, and my framing is about 1"off the concrete, so it had to move at least 6 inches.

 

[mntnresq]

Use the brass version of that Oatey drain. The whole thing is much more sturdy. On the plastic ones, the bottom nut has a tendency to pop off the threads.
You can definitely swing the trap "on itself". 2 inch No hub coupling (not a union) properly tightened with a t-torquer wrench is ok to use (not a union).
Use a proper drain wrench too:
Oatey 42239 Brass and Plastic No-Calk Shower Drain Wrench, Stainless Steel
You are on the right track, but you might find a solo plumber in the area to get this done right without having to buy a few tools.

Thanks. I will go with the brass one.

I went ahead and did the rotated trap. I did have to extend the horizontal run about 3", but I guess the one coupling shouldn't cause too much trouble.

I did do some more digging last night and realized what I thought was a wye, was actually just a 45, going into a lateral to the main, so I could have cut it all back a bit more, and straightened the trap out (still can if I have some sort of issue with this one) but figured I'd try to easier option first.

Thanks for everyone's help.