# Shower valve rough-in



## mpt1123 (May 20, 2008)

Hello:
I'm rebuilding my master bathroom shower and installing a Kohler valve. The rough-in instructions state that I should have between 2 3/4" and 3 1/2" from the centerline of the input lines to the front of the finished wall. 

The valve itself is 3 1/4" deep. I was planning on mounting this to a 2x4 between the studs, but the 2x4 is 1 1/2". Add that to the 3 1/4" for the valve and I'm at 4 3/4" before I add the finished wall of 1/2" durock and 1/4" tile.

Even if I swap out the 2x4 for a 1x4 that only takes off 3/4" and brings me to 4". 

Am I missing something here? How am I supposed to mount this valve?

Thanks,
Mike


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## mmhendrie (Mar 13, 2009)

take a look 7-8 posts down to my post "any plumbers out there?" - it has a photo of what i did - i'm no plumber, but everyone seemed to think i was on the right track...


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## mpt1123 (May 20, 2008)

Geez. Sorry about that. I did a search on shower valve rough-in with no useful hits. 

I'm thinking of doing something similar. Essentially creating a box of 2x4's ripped down to 3 1/8 wide, then attaching 3/8" plywood to the back, then attaching the 2x4's to the upright studs. The bottom of the box would have 2 inputs for water lines and the top of the box would have 1 output for the shower. 

Nice idea. Thanks for the help.

Mike


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## kenmac (Feb 26, 2009)

Incase you didn't find his post ..........http://www.diychatroom.com/f7/any-plumbers-out-there-41431/


installation instructions won't always work ..Every situation is different....Create a way to install it so that it's a good mount & works out for you


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## wrangler (Oct 9, 2008)

mpt1123 said:


> Hello:
> I'm rebuilding my master bathroom shower and installing a Kohler valve. The rough-in instructions state that I should have between 2 3/4" and 3 1/2" from the centerline of the input lines to the front of the finished wall.
> 
> The valve itself is 3 1/4" deep. I was planning on mounting this to a 2x4 between the studs, but the 2x4 is 1 1/2". Add that to the 3 1/4" for the valve and I'm at 4 3/4" before I add the finished wall of 1/2" durock and 1/4" tile.
> ...


 If you use a 1x you shold have plenty of room, because that leaves you:
2 3/4" to the end of the stud
+ 1/2" Durock
+ 1/4" tile 
= 3 1/2"


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## JDC (Mar 11, 2008)

the instructions read "from the center of the input lines"? If thats the case the "input" or waterlines are usually at the centerline of the valve itself. If the valve is 3 1/4" deep the center of the waterlines are 1 5/8". Youre tacking on the entire depth of the valve and not what the instructions are telling you which is center of the waterlines.


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## mpt1123 (May 20, 2008)

Guys:
The water lines are in the back and the center is about 1/4" from that.
That means I have about 3" but I can't ignore the 1/4" in the back, it has to go somewhere. 
Here's what I did. I built a box using (2) 2x4's (one on the top and one on the bottom.) I ripped them to 3 1/4". I attached a 1/4" piece of plywood to the back of the box. I notched the bottom for the (2) water lines and the top of the shower line. I installed the box 48" on center from the floor. I can use pipe straps to secure the lines to the back of the box. I may add straps to secure the valve itself. It's not much but I think it's enough - coupled with the trim kit installed after the tile work is done - to keep things nice and tight. 
Thanks,
Mike


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## wrangler (Oct 9, 2008)

Are you forgetting about the finished wall? The way I read your post is that the valve end will now be flush with the end of the stud wall, but you will then be adding the durarock, thinset and tile. If you leave it too short, the handle will be hitting the escutcheon plate and be either hard to handle or, depending on the type of handle, not able to shut off all the way... unless I am missing something here.


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## mpt1123 (May 20, 2008)

Guys:
Sorry for the confusion. Let me try this again.
The valve has a flat plastic disc about 6" in diameter attached to the front. The distance from the disc to the back of the valve is 3 1/4". I assume that this disc is to be flush with the framing. There is a plastic ring that attaches to this disc that is 3/4" thick. I assume that this ring is to be flush with the finished wall.

Counting the framing (3 1/2"), the durock (1/4"), the thinset (1/16"), and the tile (1/4"), i have about 4 1/16" of space to work with. Into that space I need to install a 4" valve (including the ring). It's tight.

Mike


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## mmhendrie (Mar 13, 2009)

1/2 durock gives you another 1/4 onto what you have there...


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## mpt1123 (May 20, 2008)

Sorry. My mistake. The Durock is 1/2".

That gives me about 4 5/16" for a 4" valve. Tight.

Mike


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## pf55112 (May 17, 2009)

*Installing that same valve...question about access*

This is probably a dumb question, but are you supposed to be able to remove the valve from the "shower side" once everything is complete? That is, the cement board and tile are not installed over that plastic mounting part of the valve body assembly?


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## mpt1123 (May 20, 2008)

The installation materials included with the valve should show how to do the installation. If I remember correctly, the durarock and tile are installed around (but not touching) the plastic.


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## lifeisadimensio (Dec 5, 2010)

wrangler said:


> Are you forgetting about the finished wall? The way I read your post is that the valve end will now be flush with the end of the stud wall, but you will then be adding the durarock, thinset and tile. If you leave it too short, the handle will be hitting the escutcheon plate and be either hard to handle or, depending on the type of handle, not able to shut off all the way... unless I am missing something here.


While the original poster is likely finished by now, I am tearing out the walls for my shower and need to make similar decisions.

The key to me is wrangler's posting and image. The cavity into which the valve must fit includes:
-- 3 3/8" width of the vertical 2x4 wall stud, plus
-- 3/4" for the thick finished wall thickness (1/2" of the durock, plus the 1/4" of the tile). 

That's 4 1/8" of total depth available. 

The image shows that for a thick wall (up to 3/4"), the finished surface of the wall should be up to 3 1/4" forward of the centerline of the 1/2" hot and cold input pipes. Adding 1/4" for the other half of the hot and cold input pipes, that makes 3 1/2" from the finished wall surface (tile in my case) to the back of those pipes. 

That leaves 4 1/8" (depth available) minus 3 1/2" (needed for valve) = 5/8" of depth still available for example for connectors, pieces of 1/4" or 1/2" thickness wood between the vertical 2x4 wall studs for attaching pipes, valve body, etc.

That also leaves everything on the valve forward (to the right) of the finished wall line in Wrangler's image sticking out of the wall far enough for the faucet handle(s), face plate, etc. to work and not too far to seal properly.

Again, assuming a thick (3/4") finished shower wall, when I drill the holes through the vertical 2x4 wall studs for my hot and cold pipes to pass (if any studs are in the way), the center of the hole will be 5/8" plus 1/4" = 7/8" forward of the rear of the vertical 2x4 wall stud.

Holding (with one hand) a small piece of 1/2" durock with a small piece of 1/4" tile in front of the 2x4 stud, and holding the valve up in place with the other hand, I should be able to double check my logic. Adding the faceplate, handle, etc. to the valve may help to make it even more realistic.

But, it'll be a while as I have a lot of other stuff to do first.


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## tfsboroga (Dec 24, 2015)

*Installing a new Shower Valve*

My existing shower valve is no longer working well and after opening the wall to gain access, see there are 4 copper 1/2" lines going into it rather than the 3 I would have expected. My replacement valve has 3 as I would have expected.

Any Ideas on what this 4th line might be?


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## mpt1123 (May 20, 2008)

I'm guessing that the old valve had hot and cold lines coming in, a line for the shower coming out, and a line for the tub (which may be capped).


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## TheEplumber (Jul 20, 2010)

mpt1123 said:


> I'm guessing that the old valve had hot and cold lines coming in, a line for the shower coming out, and a line for the tub (which may be capped).


This is typical. The drop for the tub may even have a strap on it to anchor it in the wall


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