Basement Bathroom Plumbing

[Supperfly17]

Hello again, A few questions:

My builder left me with a 11/2 inch shower drain in the corner that i have to convert to 2 inch and move it.

1. Can I tap into where the red circle is (this is the main drain line, 4inch) and make it 2 inch to go to where the plumb bob is for my new shower drain line.

2. What do I do with the old shower drain, the green circle. Where do I cut it off? As You can see where the blue circle is, it is tied in with the vanity drain line.

3. What type of cement/concrete mix should I use to cement the flood back in, once my drain lines are cut?

Thank you for your help.

 

[Cacher_Chick]

The existing shower drain is installed to wet vent through the vanity vent. If you cannot re-route but maintain that connection, you new drain will require a seperate vent before the connection to the main line.

A 1-1/2" shower drain is commonly accepted in Canda plumbing codes.

 

[Sponsor]

 

[Supperfly17]

The existing shower drain is installed to wet vent through the vanity vent. If you cannot re-route but maintain that connection, you new drain will require a seperate vent before the connection to the main line.

A 1-1/2" shower drain is commonly accepted in Canda plumbing codes.

Not sure what a wet vent is, but there is a vent running the way you described it. So I was thinking of doing it this way, and you are saying I cant do it this way?
Cant I just cut the 1.5 inch pipe and cap it off and leave the rest as is. And then just tap into the 4 inch pipe with a 4x2 WYE as i drew it up.

 

[Cacher_Chick]

No, the vent connection must be between the shower trap and the connection to the main line. Without a proper vent in place, the trap will siphon and sewer gases, drain flies, etc, will come back up through the drain.

 

[Supperfly17]

Would this be acceptable? Or how would you recommend I do it?

 

[CountryBumkin]

I'm not a plumber, so I don't know if this is feasible/allowed: but is there enough room between top of existing pies and underside of concrete slab to run the shower pipe "over" the existing pipe as shown in this drawing?

 

[Supperfly17]

Perhaps that would work. But someone also told me, not sure if its true that my original way will work because I am not changing the distance from the air vent if I tap into the 4" pipe for my shower drain. The distance will still be the same to the air vent. Or is it a big no-no to have the shower drain come off the 4" toilet pipe, and it always must come off the main vanity line.

 

[Cacher_Chick]

If you wye directly into the toilet line without a seperate vent, the flow of water from flushing the toilet will siphon the showers trap. This is why we have basic rules of plumbing, and plumbing codes to enforce those rules.
When it is not done correctly, there will be nothing but problems down the road...

 

[Supperfly17]

Thank you for the reply. What would your solution be, to move the drain as in the first picture where I want it. What would you do?

 

[Jadziedzic]

Could you use a linear shower drain located parallel to the left-hand wall in your picture, feeding into that existing 1-1/2" drain line instead of locating the shower drain where the plumb bob hangs (essentially relocating the shower P-trap to the area of the green circle on your diagram)?

 

[Cacher_Chick]

Thank you for the reply. What would your solution be, to move the drain as in the first picture where I want it. What would you do?

You will likely need to access the line further downstream so that the vent can come up within the wall to go through the roof or otherwise tie into the existing venting system. We cannot see the pitch and depth of the pipe there, but it appears unlikely that you would be able to connect up where the old connection was.

 

[Supperfly17]

What do you think of making it this way. I can keep the pitch constant(the same) on both the vertical and horizontal run. My 1.5 inch pipe would run over top of the 4" toilet pipe.

 

[Supperfly17]

Or if that way doesnt work, perhaps this way would?

 

[Cacher_Chick]

If there is adequate depth below the floor to maintain proper slope, yes, that would work.

The bends need to be long turn 90's or 45's put together. Because the are more than 135 degrees of change in direction, the shower drain will be required to have an accessible cleanout in the floor.

 

[CountryBumkin]

I think this bend is too tight for a drain router to make. If the shower clogs your going to have a hard time clearing it.

 

[CountryBumkin]

Would this work (gets rid of shower drain loop).
But I'm not sure about venting the shower trap.

 

[Supperfly17]

Dont think it will because the shower drain needs to come off the vanity line, or as catcher said if its done that way when the toilet is flushed it will siphon in the shower drain

 

[hj]

There is no way you can run the line OVER the main drain wihout creating an "S" trap for the shower, since it will be higher than the vent connection. The double Y would require a vent between the trap and the main line connection.

 

[Cacher_Chick]

That is my error, as of course hj is correct. It it not possible to make that run without exceeding the allowed drop in the line, which will create an S -trap.

 

[Themp]

Are you allowed to just run a pipe from the new shower drain to the plumbed P-trap that now exists if the slope is ok? Does the P-trap have to be under the shower drain? I ask because I had a leak in my second floor shower and had to remove a portion of the dry wall ceiling and there was no P-trap under the drain, the drain connected to a 90 degree elbow and then ran two joists over to a P-trap.