Slab on Grade - Missing Bathtub Trap?

[Paul E.]

House was built in 1969, slab on grade, single story, located in Texas. I'm converting the master bathroom tub to a shower.

After pulling the cast iron tub out, I noticed two things.
1. I seem to be missing the compression nut on the 1-1/2" copper drain line.

2. Where's the p trap?

The copper drain line goes down into a cast iron hub. Is there a p trap at the bottom of the cast iron riser? I think the copper drain line has been leaded into a bushing, which was leaded into the cast iron hub?

 

[Mr tee]

You will need to keep digging to see if the hub is on a trap. You are not missing a slip joint nut & washer, the tailpiece was threaded into the tee.

 

[Sponsor]

 

[Paul E.]

Ok, I will continue digging down to see if I can find out what's going on.

Does the unthreaded end of the tee, connect to the sheared end of the pipe drain? I would have thought a nut would have held them together, same as the leg that runs to the bathtub drain.

 

[Tuttles Revenge]

Does the unthreaded end of the tee, connect to the sheared end of the pipe drain? I would have thought a nut would have held them together, same as the leg that runs to the bathtub drain.

The brass tube that fit inside of the tee had teeny tiny threads that threaded up into the tee.

Its likely that the cast hub is a trap. However I would suggest replacing a cast trap with a plastic trap. Cable snakes have a really tough time getting past the radius of a cast iron trap.

Also, copper in direct contact with concrete is being eroded away. And the PH balance of the soil can damage copper tubing.

 

[WorthFlorida]

Ok, I will continue digging down to see if I can find out what's going on.

Does the unthreaded end of the tee, connect to the sheared end of the pipe drain? I would have thought a nut would have held them together, same as the leg that runs to the bathtub drain.

Is there any pipe still in the tee. You should see the other end of the sheared pipe. Take a look at this tub drain. No slip nut on the bottom.

Everbilt Trip Lever 1-1/2 in. 20-Gauge Brass Pipe Bath Waste and Overflow Drain in Chrome SH-7200-N-01-05-1 - The Home Depot

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www.homedepot.com

 

[Tuttles Revenge]

Tub drains tees have internal and slip joint threads... the internal threads are on tubular... so making thin metal thinner..

 

[Paul E.]

Just as ya'll said, there was a bit of sheared pipe inside the tee fitting. That's crazy to me that it would be threaded internally AND externally.

I continued digging down, and was able to find a cast iron p trap. It's hard to see in the photos, but the side of the p trap reads 2SV.

I'd like to replace the copper drain line with PVC. Is a doughnut in the cast iron hub my best option? Or possibly a fernco flexible coupling on the portion of copper pipe rising out of the cast iron?

 

[Terry]

A copper to plastic mission coupling. Or drop down further to the cast hub on the p-trap with a donut. You have options.

 

[Paul E.]

Working on bringing this saga to a conclusion. I ended up digging out the old cast iron p trap, and now am faced with two options for routing the new PVC pipe up to the shower drain location, and would appreciate any recommendations on which option is the better.

Here's an overview of the box out, with the waste line I am tying into on the right. Two copper waterlines run through the opening. The string line is showing where my shower drain will end up.

Another shot of the existing waste line.

P trap routing - Option 1

P trap routing - Option 2

I like that option 1 is a shorter run of pipe than option 2. Not sure if I like that the riser will come up between two water supply lines. Is that OK?

Option 2 has the new p trap closer to the original cast iron p trap location as shown below.

 

[John Gayewski]

Option 1.

Option two doesn't give you any way to cut pipe to length from above after the base is set.

 

[Paul E.]

Thanks for the reply John. Are there any reasons to avoid running the waste line between the supply lines?

The only code I could find concerning waste lines and supply lines was about separation distances in a trench.

 

[John Gayewski]

Thanks for the reply John. Are there any reasons to avoid running the waste line between the supply lines?

The only code I could find concerning waste lines and supply lines was about separation distances in a trench.

No. Your water is above the waste line.