Shower remodel

[Russ13]

I'm changing a shower, fiberglass, insert to a tiled shower. I'm expanding the shower around 3" wider so I have to move the 1 1/2" stack that is "inline" with the shower drain( around 2/3 feet from the shower drain). The stack is in the wall where the shower supply line is located. My question is this. The previous PVC shower drain was all 1 1/2" line. I'm finding that it needs to be or is "supposed" to be 2" line. It does eventually dump to a 2" drain(around 4/5 feet away from the drain). I could put about 2 to 2 1/2 feet of 2" PVC(ptrap to straight pipe) and then reduce down to the 1 1/2" pipe, right before the stack, and then it will go back to the 2" straight pipe, eventually out to the 3" main. So that would give me only around a foot to a 1 1/2' of inch and one half of PVC from the drain. I really want the full length to be 2" but the joist/ HVAC hard ducting location makes it almost impossible because the 2" fittings are larger/longer than the 1 1/2" fittings. Do you think this is doable or should I just leave it as it was before(1 1/2" PVC the whole way)?? Thanks for any help.

 

[Terry]

When I encounter a 1.5" shower drain I leave it that size.
I will use a 1.5" p-trap with a 2.0" x 1.5" reducer above the p-trap for the 2" shower drain.
Most shower heads are restricted to 2.5 GPM or less.
A tub uses a 1.5" trap and trap arm. Not current US code, but it works.

 

[Sponsor]

 

[Russ13]

When I encounter a 1.5" shower drain I leave it that size.
I will use a 1.5" p-trap with a 2.0" x 1.5" reducer above the p-trap for the 2" shower drain.
Most shower heads are restricted to 2.5 GPM or less.
A tub uses a 1.5" trap and trap arm. Not current US code, but it works.


View attachment 60864

Thanks, Terry! I was reading some of the forums where they have reduced a 2" to 1 1/2" because they couldn't get to that area to make it ALL 2" to the main. They said it would make a "dam" and cause issues later on, because of hair and what not clogging up the reduced area, so it makes since to just leave it at 1 1/2" all the way since that was the way it was before. We will have a "in ceiling" rain head and probably another shower head and "maybe" an hand held sprayer.

 

[Dj2]

You can only increase your drain pipe going in the direction of the drain flow, not reduce it.

 

[Terry]

I always start with 2" at the drain and reduce on the vertical, like a funnel. We're talking two inches.
I can see how some really have a hard time with a 2" funnel that is 2" long going into a 1.5" vertical.
So...........you're really running a 1.5" into your 2" drain?

 

[Russ13]

I always start with 2" at the drain and reduce on the vertical, like a funnel. We're talking two inches.
I can see how some really have a hard time with a 2" funnel that is 2" long going into a 1.5" vertical.
So...........you're really running a 1.5" into your 2" drain?

Good news! I've figured out a way to be able to run all 2" drain line from shower to the main. I'm having to remove hard HVAC duct to be able to place the drain where I need. It's okay because it's just a feed to the unfinished basement that I can move later on with, possibly, flex ducting. Just waiting on a 2"x 2"x 1 1/2" sanitary tee for the stack.

 

[Russ13]

Good news! I've figured out a way to be able to run all 2" drain line from shower to the main. I'm having to remove hard HVAC duct to be able to place the drain where I need. It's okay because it's just a feed to the unfinished basement that I can move later on with, possibly, flex ducting. Just waiting on a 2"x 2"x 1 1/2" sanitary tee for the stack.

 

[Plumber69]

Is that a union ptrap? and did you tee it in?

 

[Russ13]

Is that a union ptrap? and did you tee it in?

It is a union. I find now I should have used a conventional P-trap. I did two 90's. Is that not sufficient?

 

[Terry]

The p-trap should be solvent weld (glued)
If you can swing the swivel, you can lose the 90.
If you need to angle over, a 45 is always much better. At some point you will need to snake the drain and the less change of direction the better.