Sink Drain used as a shower drain, should I dig it out?

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Old 04-11-15, 03:23 PM
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Sink Drain used as a shower drain, should I dig it out?

I am installing a shower base where a tub/shower used to be. I've got the old tub out and am working on the plumping for the new shower base. I've found
that the previous installer used a sink drain for the tub/shower which also protrudes from the ground and goes deeper underground.

Its much thinner and flimsy than actual 1.5 drain pipe. My question is should I continue digging this pipe out to get to wherever is connects or will it be sufficient to tie my new drain into? They used a tar like substance around the pipe which makes digging a little tough and I'm not sure if its connection is easily accessible.
 
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Old 04-11-15, 03:38 PM
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Showers need a 2" drain not 1-1/2".
 
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Old 04-11-15, 04:25 PM
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That actually looks normal and would accept the tail piece from the tub overflow that marries to the "T" from the tub drain and then go on to the trap that is in the floor. But, as Joe mentioned, code says that a shower drain needs to be 2" not the 1 1/2" that you find with a tub.
 
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Old 04-11-15, 04:26 PM
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If this was a tub, there should be about a 12" x 12" square "sandbox" surrounding this pipe, encasing your trap. None the less, you will need to dig up the entire run to where it connects into the main drain and change it to a 2" line.
 
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Old 04-11-15, 04:54 PM
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The piece pictured does accept the tub drain and overflow pipe. There is around a 12"x12" area cut out in the slab where the pipe goes. If I continue digging will I be able to reach the main drain line in that 12"12". Is this something an inspector would look at when it I sell my home?

My original plan was to install a short 1-1/2" flange (sink drain) to existing outlet, then expand to a actual 1-1/2" pvc pipe with pvc cement, run 1-1/2" to meet up with a 2"-1-1/2" reducer just below the drain.

I will be using a low flow shower head under 2.5gpm
 
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Old 04-11-15, 05:10 PM
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I know you are trying to justify it, but you cannot just adapt up to a 2" fitting and make it right. If you dig out the sand/stone in the pit, you will find your trap. To do it right, you will need to dig up concrete and run a 2" line to your main line and tie it in, repairing the concrete when done.
 
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Old 04-11-15, 06:18 PM
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I've been following How to Fit a Shower Tray on installing the shower base.

It states "Most shower drains are designed to receive 2-in. piping, while most existing tub drains are 1-1/2 in. The plumbing code calls for the transition to be made with a reducer directly below the shower (Photo 10), nowhere else."
Hopefully this will work for me.

I was not aware of this drain code before posting this thread. Looks like I'll need to find a building/plumbing inspector to check it out. If its a no go, I'll have to put another tub in before tearing up the foundation, its just not worth the cost and I certainly don't want to complete the job only to have to tear it all back down when I sell the house.
 
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Old 04-11-15, 06:41 PM
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The problem is the 1" may not be able to carry away the water fast enough to avoid filling the pan. Often articles like that are written by people who read an article written by someone who read... and none actually have training or experience in plumbing.
 
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Old 04-12-15, 12:45 PM
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finally got to 2" pipe

I have dug all the way down to the P trap, where thankfully the p trap appears to be 2". Problem is There is a threaded hex connection that connects the 1-1/2" pipe to the 2" P trap. Its way down in the hole and Im not able to get a pipe wrench on it. I need to be very careful removing the because the p-trap goes under the foundation so I do not want to damage it trying to remove the connection.

Any advise on how to remove this pipe from the p trap without damaging it is greatly appreciated.Name:  2inchdrain1.jpg
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Size:  34.0 KBName:  2inchdrain.jpg
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Old 04-12-15, 02:10 PM
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That is NOT a threaded fitting, it is a solvent welded (glued) reducer bushing. The only way to remove it is by careful surgery, probably with a hand die grinder or a Dremel-like hand grinder finishing the job with a two-inch RamBit.

https://www.plumbingsupply.com/rambi...aver-tool.html

The alternative is to excavate the entire trap and cut it out, adding a coupler and new trap to the existing two-inch pipe as needed.
 
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Old 04-12-15, 03:40 PM
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Not good news. It looked like it would be threaded as it had a hex fitting. I'm glad I didn't try to hard to get it to turn. Is this something a master plumber would be able to handle? This maybe a little more than I am willing to take on. Maybe I should just tap into the 1-1/2 pipe that is connected to it for my drain. Frustrating being so close to 2" though.
 
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Old 04-12-15, 03:53 PM
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Master plumber? I should think a third year apprentice could handle this fairly easily. The biggest problem is that you have lie on your belly to get close enough to do the work. Second biggest problem is coming up with the scratch to buy the RamBit for what will most likely be a one-time job. You might be able to rent a RamBit, I have never tried so I simply don't know.

If you DO call a plumber make sure you tell him exactly what you have and ask specifically if he has the tools to cut out the reducing bushing. If he/she simply gives broad assurances that he/she can handle anything I would advise calling the next one on the list.

I would not even consider using the 1-1/2 inch for a shower drain. Besides being contrary to the plumbing code it simply doesn't make sense to take the chance.
 
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Old 04-12-15, 03:54 PM
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This maybe a little more than I am willing to take on.
It is really an easy DIY job. Anybody with a hack saw or Sawzall can do it. Just cut the old 2" trap off and glue a new one on. Should cost less than $10 to do and less than 15minutes of time.

I would suggest though you get the new shower pan first so you know exactly where the drain needs to be.
 
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Old 04-12-15, 04:09 PM
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I looked at the picture again and Ray is correct. I had thought the concrete was up to the trap but now I see it is just dirt. Excavate the dirt until you have a clear shot of the two-inch pipe and then cut the trap out completely, add a coupler and whatever "fitters" necessary to align the trap and the new shower pan and you are all set.

A plumbing company would likely charge in excess of $150 for $10 worth of parts and maybe an hour of labor.
 
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Old 04-12-15, 05:34 PM
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The p trap travels diagonally to the top right of the zoomed out picture, not much room until it goes under the foundation. It is not encased in cement, however the cement becomes jagged with not much clearance from where it goes under. I've got some Rebar in from of the trap, should I cut it to gain better access to excavate underneath the trap?

I'll keep digging and see if I can get access to the pipe going into the trap.
 
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Old 04-12-15, 06:13 PM
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1/2 of the other end is encased in concrete (hard to see in picture). Should I chisel the concrete around it?Name:  p trap.jpg
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Size:  50.0 KB I don't want to damage to pipe.
 
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Old 04-12-15, 06:14 PM
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Lets see what more digging shows.
not much clearance from where it goes under.
Enlarging the hole if needed shouldn't be difficult. Yes, chisel the concrete. You may need to score the concrete with a circular saw (diamond or carbide blade) and open the hole a bit more.
 
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Old 04-12-15, 06:37 PM
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I would do as Furd suggested and grind out the 1 1/2" stub from the 2" coupling. Tool will run about $25. To me, cheaper than labor of cutting concrete, rebar, etc.
 
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Old 04-12-15, 07:45 PM
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Either way is good and is cheaper then a plumber but if it is a premade shower pan the drain might not line up.
 
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Old 04-29-15, 01:04 PM
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Did you ever get the pipe fixed? You probably have by now. For anyone who comes by in the future. I've taken pieces out like that with a chisel and hacksaw a couple times on bulkhead fittings(Who wants to pay $20 for a fitting that is outside anyway?). I've also removed one with a heatgun. Heat it up and roll it out. I've seen someone use a hole saw too.

A video that shows the heat gun method.

https://www.youtube.com/watch?v=JCMQ6OA84OA
 
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