# Bathtub to shower conversion with a liner..



## cityplumbing (Jun 12, 2010)

I was doing a bathtub to shower conversion. I removed the old waste and over flow and dug down to a 2in p-trap and ran my pipe up to a new 2in shower drain. I'm doing a liner on this one. Thought it would be a hell of a lot less work if I could connect to the 1-1/2 but I didn't feel comfortable with doing it that way being that I only see 2in drains for shower pan liners and know that reducing in the direction of flow is a no no. 

I'm dreading the day that I find a 1-1/2 drain line for the tub and the main is in the next room...

Has anyone reduced the 2in shower drain to 1-1/2in or used a 1-1/2in drain for a liner?

Any thoughts?


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## bizzybeeplumbin (Jul 19, 2011)

In my code, both UPC and IPC, the shower needs to be 2".

A 11/2" is ok for a tub / shower combo only. So, even if one day there is 11/2" and 2" in the next room, if its a shower, it needs to be 2"


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## OldSchool (Jan 30, 2010)

Up here we are allowed 1 1/2 if it is in the floor joist.... 2" if its in the concrete floor.... as per fixture units... all it really has to be is 1 1/2


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## cityplumbing (Jun 12, 2010)

I'm showing In Florida building code 1-1/2 has 2 fixture units and it's showing the maximum fixture units for a 1-1/2 building drain with 1/4in pitch and 1/2in pitch to be 3 fixture units...


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## OldSchool (Jan 30, 2010)

I am pretty sure... but I would have to double check our code book here 

1 1/2 is 4 fixture units
2 is 6 fixture units


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## bizzybeeplumbin (Jul 19, 2011)

Look in the chart under shower, see if it says 2" trap. Bathtub 11/2"

2" min under slab here. But even if it's a shower above slab, it's 2" Trap size is what matters, not necessarily DFU'S


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## OldSchool (Jan 30, 2010)

cityplumbing said:


> I'm showing In Florida building code 1-1/2 has 2 fixture units and it's showing the maximum fixture units for a 1-1/2 building drain with 1/4in pitch and 1/2in pitch to be 3 fixture units...


if 1 1/2 is 2 fixture units in florida then what size of pipe on a double kitchen sink?

each sink bowl is 1.5 fixture units here... that would be 3 FU


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## cityplumbing (Jun 12, 2010)

Shower minimum trap size is 1-1/2. and kitchen sink is 1-1/2.


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## 100 Watt (Aug 11, 2011)

Here you can run 1.5" to a shower. Most of us don't, but it comes in handy on a remodel like you're doing. Just install a reducing coupling immediately below the base.

Code just changed though on big custom showers. We have to figure max water useage and size the drain accordingly. We'll be running 3" to some of these based on body sprays and what not. Hopefully they'll all fit within joist spaces!


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## OldSchool (Jan 30, 2010)

cityplumbing said:


> Shower minimum trap size is 1-1/2. and kitchen sink is 1-1/2.


Thats what I figured

But if it is in a concrete floor always best to go 2"


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## bizzybeeplumbin (Jul 19, 2011)

cityplumbing said:


> Shower minimum trap size is 1-1/2. and kitchen sink is 1-1/2.


Only in Florida! LOL. Your good then if its in your code. We just cant do it here. I don't thing I have ever seen an 11/2 shower drain, I am sure it must be sold only in Florida!


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## cityplumbing (Jun 12, 2010)

bizzybeeplumbin said:


> Only in Florida! LOL. Your good then if its in your code. We just cant do it here. I don't thing I have ever seen an 11/2 shower drain, I am sure it must be sold only in Florida!


Your right!! Only in FL :laughing:.. I haven't seen a 1-1/2 shower drain either, this is the problem.. Reducng the 2in shower drain wouldn't be right no??


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## OldSchool (Jan 30, 2010)

bizzybeeplumbin said:


> Only in Florida! LOL. Your good then if its in your code. We just cant do it here. I don't thing I have ever seen an 11/2 shower drain, I am sure it must be sold only in Florida!


You are allowed to reduce the drain size... use a bushing in the shower drain


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## cityplumbing (Jun 12, 2010)

OldSchool said:


> You are allowed to reduce the drain size... use a bushing in the shower drain


Thought you can't reduce in the direction of flow? I was on the fence with this one being that the top of the drain that screws in is 1-1/2.


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## bizzybeeplumbin (Jul 19, 2011)

that's what I was going to say, put a busing in the shower drain, only place I would think it would be legal.


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## RealLivePlumber (Jun 22, 2008)

They just changed our code. Single shower head, 1 1/2" drain. 

Add a handheld, or anything else, 2" drain. 

Anything underground, 2" min. 

If you use a bushing in the wet set strainer, it is not a reduction. Look closely at it.


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## Richard Hilliard (Apr 10, 2010)

cityplumbing said:


> I'm showing In Florida building code 1-1/2 has 2 fixture units and it's showing the maximum fixture units for a 1-1/2 building drain with 1/4in pitch and 1/2in pitch to be 3 fixture units...


 Florida code does require a 1.5 inch drain to tubs however underground 2 inch is the minimum size. The trap will be 2 inch and a bushing will be used to decrease to the 1.5 trap adapter.


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## Flyguy199 (Sep 20, 2011)

I have always used 2 inch, but 1 1/2 is allowed by code here if it is a single shower head.


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## drtyhands (Aug 16, 2008)

I've seen some pretty caked up tailpieces.I have no idea what some homeowners are using in the shower for hygene,some of the deposits are like friggin sandstone.

Is it the possiblity that the larger 2" cast iron drain does not clean itself as well as the 1-1/2" on tubs.

Starting to think it's the cast iron.
If so 1-1/2" in theory(not considering individual code) could handle the volume of 1 head.

I would never use it in a custom with multiple fixtures.

1-1/2" allowed except underslab is a nice touch.Helps out if someone rolls the dice on remodeling up gpm.


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## BROOKLYN\PLUMB (May 21, 2010)

100 Watt said:


> Here you can run 1.5" to a shower. Most of us don't, but it comes in handy on a remodel like you're doing. Just install a reducing coupling immediately below the base.
> 
> Code just changed though on big custom showers. We have to figure max water useage and size the drain accordingly. We'll be running 3" to some of these based on body sprays and what not. Hopefully they'll all fit within joist spaces!


Now that sounds like some logical code! 
Because it's really about how much max Agua is going down the hole!


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## Redwood (Sep 8, 2008)

drtyhands said:


> I've seen some pretty caked up tailpieces.I have no idea what some homeowners are using in the shower for hygene,some of the deposits are like friggin sandstone.


http://www.johnbridge.com/how-to/how-to-remove-efflorescence/


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