Hello everyone - First thanks in advance for the expert help!

I am adding a shower to a powder room on the second level of my house. The room is 6.5' x 5.5' with only a toilet and sink. There is a 3 inch copper sewer line directly behind the toilet - this house was built in the 70's.

I want to add a 32 inch shower stall directly across from the toilet. The easiest way I can think of would be to cut the copper toilet waste line and replace it with a PVC 3" WYE for the toilet with a 2" inlet for the shower. I would attach the PVC to the copper with a no hub connection before it meets the main.

A couple questions about this setup? Would this meet code or am I setting myself for problems down the road. Also, would I require any additional venting?

Thanks again!
-ej

Hi EJ:

The way you have this drawn you will need to add an 1.5" vent to the 2" shower drain and connect that into the sink vent. I'm thinking it may be better to connect into the sink drain... IF IT IS A 2" PIPE...?? This way you can use the sink vent to WET VENT The shower...;)

Let me know if the pipe is 2"...

MARK

Hi EJ:

The way you have this drawn you will need to add an 1.5" vent to the 2" shower drain and connect that into the sink vent. I'm thinking it may be better to connect into the sink drain...IF IT IS A 2" PIPE...?? This way you can use the sink vent to WET VENT The shower...;)

Let me know if the pipe is 2"...

MARK

Thanks Mark!

The sink drain is about 1 foot above the floor level so I couldn't connect into it without a pump, and besides it is only 1.5".

Where would you suggest I put the 1.5" vent on the shower drain?

Thanks,
-ej

Got you...

You can connect a 2"x1.5" sanitary tee fitting... rolled above the center line of the 2" shower drain (see image)... anywhere within 5 feet, but no closer than 1 foot of the shower drain PTRAP.

You want to run that vent upstairs and connect it into the vent stack at 42-48" off the finish floor. Here, the vent from below must connect into the lavatory vent or the vent stack at least 6" above the flood level rim of the highest fixture on the floor... i.e. the lavatory... why we give a general measure of 42-48" off the finish floor...;) The connection should be by an inverted sanitary tee fitting.

Vents must pitch (1/4" per foot) so that any rain water that gets into them drain naturally into the drain system... so keep that in mind, too.

Let me know if it all makes sense...

Got ya....

You can connect a 2"x1.5" sanitary tee fitting...rolled above the center line of the 2" shower drain (see image)...anywhere within 5 feet of the shower drain.

You want to run that vent upstairs and connect it into the vent stack at 42-48" off the finish floor. Here, the vent from below must connect into the lavatory vent or the vent stack at least 6" above the flood level rim of the highest fixture on the floor...i.e., the lavatory...why we give a general measure of 42-48" off the finish floor...;) The connection should be by an inverted sanitary tee fitting.

Vents must pitch (1/4" per foot) so that any rain water that gets into them drain naturally into the drain system....so keep that in mind, too.

Let me know if it all makes sense...

What do you mean by an inverted sanitary tee? Attached is a photo of the project if this helps...

Thanks again Mark!

-ej

Glad to help!

Here's a pic of what I am talking about...

You need to run that vent upstairs and connect into the copper pipe as drawn.

You will need 3" copper x 3" pvc shielded transition clamps... see other picture at bottom right... ;) These may not be available at a home supply... may need to go to a plumbing supply company.

Let me know if you have questions... o.k.?

MARK

Glad to help!

Here's a pic of what I am talking about...

You need to run that vent upstairs and connect into the copper pipe as drawn.

You will need 3" copper x 3" pvc shielded transition clamps...see other picture at bottom right...;) These may not be available at a home supply...may need to go to a plumbing supply company.

Let me know if you have questions...o.k.??

MARK

I think we are on the same track, you just draw better than I do...

What do you thin about the washer drain in the attached?

Thanks,
-ej

I've drawn a few of these... ;)

1) Put the 1.5" vent in the stud bay I drew...bet it will be easier than working around the toilet water pipe....never mind that a wye fitting with a 45 degree fitting is considerably wider than you drew it!

2) You will be connecting that 1.5" vent into the shower drain in your pic. Using a 2"x1.5" sanitary tee as drawn in my picture... right? Note direction of sanitary tee in my pic.

3) Where you say, "old sink VENT... it is really an old sink DRAIN... :)

4) I'm good with adding the washing machine drain at that old sink drain as long as you add a VENT at the other lavatory... see image. You could purchase a 3"old sink VENT...it is really an old sink DRAIN...:)

4) I'm good with adding the washing machine drain at that old sink drain as long as you add a VENT at the other lavatory....see image. You could purchase a 3" DOUBLE wye (or sanitary tee) and use to vent the lavatory and the new shower.

The washing machine tailpiece.. the pipe from the trap to where the washing machine connects into the drain pipe... should be at minimum 18-24" tall... so keep that in mind when roughing this in.

Back to you...

I've drawn a few of these...;)

1) Put the 1.5" vent in the stud bay I drew...bet it will be easier than working around the toilet water pipe....never mind that a wye fitting with a 45 degree fitting is considerably wider than you drew it!

2) You will be connecting that 1.5" vent into the shower drain in your pic. using a 2"x1.5" sanitary tee as drawn in my picture...right? Note direction of sanitary tee in my pic.

3) Where you say, "old sink VENT...it is really an old sink DRAIN...:)

4) I'm good with adding the washing machine drain at that old sink drain as long as you add a VENT at the other lavatory....see image. You could purchase a 3"x1.5" DOUBLE wye (or sanitary tee) and use to vent the lavatory and the new shower.

The washing machine tailpiece..the pipe from the trap to where the washing machine connects into the drain pipe...should be at minimum 18-24" tall...so keep that in mind when roughing this in.

Back to you...

Thanks again Mark..

1. I will definitely take your advice and use that stud bay
2. Sounds great on the shower vent
3. LOL, yes it is indeed an old sink drain that has never been used - frankly I'm surprised the upstairs didn't smell all these years with no trap!
4. Your drawing (red) looks much better than mine (blue). I was trying to avoid an S trap situation... Regarding the vent for the existing sink, if it hasn't been vented all these years, would the load of the shower/washing machine create any new problems? Its no problem adding the new vent, but is it absolutely necessary?

Thanks again,
-ej

YUP... very necessary. If you don't add the new vent at the lavatory then when the washing machine drains it will siphon the ptrap of the sink and allow sewer gasses into the home.


MARK

YUP...very necessary. If you don't add the new vent at the lavatory then when the washing machine drains it will siphon the ptrap of the sink and allow sewer gasses into the home.


MARK

Perfect! I will definitely add the vent for the sink. It appears I'm approaching the end of my questions here, but I have 2 more...
1. The WYE where the shower ties in with the toilet - should this be rolled above the center line as well? I know the shower line should be sloped down slightly to promote the correct flow, but just wanted to check.

2. The double sanitary tee near for the venting, could I use 2 singles in case I cannot find a double?

I will now need to move onto the feed lines, but that should be pretty simple as I intend to use PEX to feed the sink, laundry, and shower. I am contemplating using a manifold to feed the 3 units unless a less expensive option exists...

Thanks again!
-ej

1) I always roll my wyes and then roll the vent fitting above centerline too, but you don't have too... up to you.

2) You can certainly use two wyes in place of the double wye or double sanitary tee fitting.

In terms of PEX... go with the manifold... usually best overall result!

Pop back anytime... ;)

MARK

1) I always roll my wyes and then roll the vent fitting above centerline too, but you don't have too....up to you.

2) You can certainly use two wyes in place of the double wye or double sanitary tee fitting.

In terms of PEX...go with the manifold...usually best overall end result!!

Pop back anytime...;)

MARK

Mark - I have another question. Why is that sanitary tee inverted where the shower vent attaches? Also, would the sink vent tee also be inverted as well? Why would one invert a tee?

If I were to use a double WYE instead, what should the orientation be?

Thanks again, huge help!!

-ej

The sanitary tee at the shower pipe isn't inverted... the branch of the tee fitting goes with the flow of the drain.

The sanitary tee or wye fitting is installed in the 3" pipe inverted (upside down) so that the rain water that falls down the vent stack from outside will flow by gravity down the drain and the vent system.

The double wye would also be installed upside down.

The sink vent will have the sanitary tee installed normal... not inverted... so that the drain waste can flow down the drain. The rest of the vent will be pitched and rain water will flow past this fitting without issue... has no where else to go.


Back to you...