Help with a "builder" basement shower drain rough in

[TryingToPlumb]

Hey all, happy holidays. I am finishing the basement and the builder "roughed" in some stuff for a bathroom down there. Ive completed the toilet, vanity and shower water supply lines. Looking at where the shower drain is, its off center. Im not sure what to do with it or what I am really looking at. I plan on using a Schluter system for the shower but I am confused on what to do with the drain. I have attached some pictures for reference. You will see the shower drain and can see to the left what is labeled the septic vent. I believe this is a wet vent, similar to what they left for a vanity to tie in. I imagine this drain is already tied in. Thanks. I appreciate any help and feedback.

 

[TryingToPlumb]

I dug out the rough in and it doesnt look like there is a p-trap there, unless its further down. I went down 12" from the floor and its still straight pipe.

Should I be looking for a centered drain or off center? Maybe less work to do the off center since the drain is pretty close? Here are the two I was looking at. If there is something better to use, I all for it. Thanks.

https://www.amazon.com/Schluter-Kerdi-Shower-Kit-Offset-Flange/dp/B07PPPMHYH - off center

https://www.amazon.com/Schluter-Kerdi-Shower-Kit-x60-Flange/dp/B07PQT2THF - centered

 

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[Reach4]

Pour a quart of water in, and let it sit.

Then try to detect the water later by inserting a wick to see if it comes up wet. Cloth strip, cotton rope, etc.

 

[Tuttles Revenge]

Cut the cap off, pour water in as suggested and then with a flashlight, look down the drain. If you see water sitting in the drain, then it is trapped. If you don't see water standing, its not trapped.

Center is relative in a shower. It really depends on whether you consider center to be based on a measurement or a grout line. You can measure it from the inside corner to inside of curb or glass or outside of curb.. Ultimately it depends on what you want to see... And that drain can be offset slightly in the vertical with a couple offset fittings to adjust slightly to your design.

And FWIW... your "builder" did you a solid by not burying that drain under the slab which happens a lot.

 

[TryingToPlumb]

Thanks guys. Looks like there is a trap there. I was also able to catch up with the plumber who roughed it in and he said there is a bath trap there.

Do i get the offset kit then?

 

[Tuttles Revenge]

The UPC allows a shower to be installed on a bathtub rough in so long as only 1 showerhead can be operated at any time.

Installing a tile floor gives you the advantage of placing the drain wherever in that floor you want. I've never installed schluter system but most presloped foam pad systems take into consideration that your drain is not perfectly aligned with the prebuilt system. You may need to buy a spacer or filler to accomplish that. But if the center of your presloped schluter is within the buckout/hole in the concrete, then I would use a couple fittings to offset the drain to match the schluter.

Below is the style of pan you would be mimicking.

 

[TryingToPlumb]

Thank you very much! I'll see where the drain ends up when the system comes in.

So I know, are shower trap rough ins and tub/shower ones different? Thank you.

 

[Tuttles Revenge]

So I know, are shower trap rough ins and tub/shower ones different? Thank you.

Yes. Showers require a 2" trap and 2" drain (after the vent) or whatever drain is required for the amount of showerheads / gallons per minute of incoming water that needs to be drained.

A bathtub requires a 1.5" trap arm and 2" drain.

But the code will allow a shower to be installed where a tub had been roughed in so long as only 1 single shower head is able to be turned on at any time.