Shower valve depth in wall - rough in / other questions

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Old 03-21-11, 07:29 AM
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Shower valve depth in wall - rough in / other questions

I got a moen shower stall kit. It's got a head, handle, trim and valve. the instructions however are ALL pictures and really not clear.

1. How deep do I need to mount this shower valve back in the framed wall?

2. any sense in switching from copper to cpvc to run to the shower for the purpose of cost reduction and easy of installation? It's all copper right now, I just figured maybe it would be cheaper and faster to convert it over for the run to and in the shower stall.

3. returning my moen $128 kit. It's really more then I wanted to spend. any problem with something cheaper like american std? any recommendations?
 
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Old 03-21-11, 10:46 AM
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Answers:

1. There should be a black round plastic piece that is attached to the diverter. This should be flush with finished wall. So if your down to the studs, mount the diverter so that black piece will be flush with the stall kit walls. Dry fit the walls and measure from stud to surround. If sheetrock and tile you would extend the diverter 1". 1/2 for rock 1/2 for tile.

2. If copper is already there leave it. If its a new bath and there is no water pipe, and your running from the basement to upstairs, then I would run pex. But then you need the pex tools.

3. Keep the moen. If posible you should get a moentrol and not a posi temp. You will tank me when you need to change the cartridge. I have all moentrols. The home stores dont sell them.

Allthough moen goves lifetime warranty. Make sure you register the product on line.



Mike NJ
 
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Old 03-21-11, 02:48 PM
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Thanks! Just what I was looking for.
 
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Old 06-23-11, 07:50 PM
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Mike, on my new Moentrol the 'plaster ground' is white... and boy do I agree that those little 'comic books' that Moen supplies as so-called instructions are ridiculous. I talked to tech support at Moen today about that... the instruction sheet they supply with the Moentrol valve is WRONG! There's a mistake in panel #4 ... it says to cut a 4.5" hole in the wall... this works for the POSITEMP valve, but NOT the Moentrol. The plaster ground for the Moentrol is FIVE and a half inches.

It says to REMOVE the plaster ground before trimming out... so apparently the ONLY reason for that plastic part is to set the depth of the valve behind the wall... it serves no other purpose apparently. If that's true, I don't understand why it has holes in it to access the stop valves and such. Why wouldn't they just make it a solid flat piece of plastic?

Do you have any 'tricks' for accurately placing the holes that need to be cut in the cement board / Swanstone / etc ? I'd REALLY be pi55ed if I messed that up. I was thinking about making a template... is that a good plan?
 
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Old 06-23-11, 11:04 PM
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It says to REMOVE the plaster ground before trimming out... so apparently the ONLY reason for that plastic part is to set the depth of the valve behind the wall... it serves no other purpose apparently. If that's true, I don't understand why it has holes in it to access the stop valves and such. Why wouldn't they just make it a solid flat piece of plastic?
Because it usually stays in place for a while. When the plumbers get the water line inspection it gives access to the stops while leaving the cover in place. Once the cover is lost the sheet rockers come in and crude it all up.

The opening does not have to be as big as the plastic. Its only that big to access the stops.

I never used the stops in any shower valve I ever serviced or installed. ( Turn the main off ) I only use them to make sure they are open on installation. Why? They like to leak.. Some guys use them. I dont. Worst thing to have a slow drip in the wall.

Do you have any 'tricks' for accurately placing the holes that need to be cut in the cement board / Swanstone / etc ? I'd REALLY be pi55ed if I messed that up. I was thinking about making a template... is that a good plan?
Well the old saying is measure twice cut once. You need to have confidence...LOL

What I would do if it was me, and I did this with my upstairs surround, is install everything but the faucet. Then I stood in the tub/shower and measured center of drain horizontal and vertical at a height for me. The last diverter was way down by the tub. I wanted it higher so I could operate the valve at arms length while standing.

Well anyway drill your hole then install the diverter from the back. You cant miss...

I usually drill a 3" hole.

If you cant install from the back then, and you make a template or whatever, drill a very small hole first. Then if your off some then you can drill a bigger hole over some. Ya know what I mean? Once you drill a big hole theres no moving it. You would need a big remodel plate to cover it.

I like things centered so I drill first then install.

Hope this helps.

Mike NJ
 
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Old 06-27-11, 04:49 PM
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Thanks Mike... I usually measure like 10 or 20 times before I pick up a saw!

Since I'm gonna put up cement board with the surround material on top, and I have access to the back side via a closet, I think I can get a pretty good shot at marking the back of the dry fitted surround material then take it down and cut it out. I don't care if I mess up the cement board a bit, nobody will see it!

I took the 'guts' out of the valve before I soldered... didn't wanna take a chance at overheating something... and I lernt sumpin innerestin about the 'stop valves' on the Moentrol valves. They are actually SPRING CHECK valves! They work sorta the same way the boiler flow checks with the weighted disc work, except they are spring loaded.

The 'disc' in the Moen valve has a rubber washer on it, then a very light spring, then the screw mechanism. When the stop valve is fully CCW, the spring holds the disc and washer against the seat. When the valve is opened, water pressure pushes the disc up. When you close the stop valve (fully CW) the screw mechanism pushes and holds the disc and washer against the seat.

This exploded parts diagram does NOT show the individual parts. It looks like a normal stop valve guts, but it's not. Three pieces... spud, spring, disc with washer ( # 12318, notice they call it a 'stop-check' assembly):

http://www.moen.com/shared/docs/expl...ews/3550pt.pdf

I think the reason for it being a check valve is to prevent flow across the valve from cold to hot or vice versa when the tub/shower is not in use, and in the event that the pressure is different on either side for any reason... which could happen if one were to say flush a toilet...
 
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Old 06-27-11, 06:00 PM
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After perusing the web and seeing numerous postings by folks complaining that the valve handle sticks out too far when in the off position, I have to concur... after 'dry fitting' the escutcheon and handle to my newly installed valve.

There is in fact a full half inch between the back of the handle and the escutcheon when in the OFF position, and the valve installation was followed to the LETTER, and questions answered by the Moen tech support group.

The 'plaster ground' is a plastic part that screws onto the valve and stays there until the valve is trimmed out after the wall surrounds are completed. It's purpose is to protect the valve from getting 'schmutzed up' with mortar, grout, drywall compound, whatever AND to provide a guide to setting the valve depth into the wall.

This 'plaster ground' is CLEARLY embossed on the front that the valve is to be installed deep enough in the wall that the surface of this plaster ground is FLUSH WITH THE FINISHED WALL.

Moen tech support INSISTED that this was correct, so even though I 'felt' it wasn't, I did install the valve at a depth that would put the plaster ground flush with the finished wall.

Following the instructions is definitely, absolutely, NOT CORRECT.

If the plaster ground were 3/8" THICKER, setting the valve deeper into the wall, the rear of the handle would have 1/8" clearance from the escutcheon when in the OFF position, which would look and operate perfectly.

Bottom line is that if I ever install another one of these, I will mount the valve such that the plaster ground is THREE EIGHTHS OF AN INCH BEHIND THE FINISHED WALL SURFACE... OR place 3/8" spacers on the screws behind the plaster ground so that it sits higher on the valve.

It's not too late or difficult for me to move the valve back, there's enough play in the pipes to do so, but unless you want a 'washcloth hanger' on your bathroom wall, DO NOT follow the 'comic book' instructions that Moen supplies with this valve!
 
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Old 06-27-11, 06:23 PM
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What happens Troop is when the escutcheon is screwed on it puuls the body towards the wall board. I dont know if this is your case but alot of guys go to town tightening the escutcheon.

The design I think is to allow leeway. Its not set in stone. I think there is a tolerance 1/2" each way. That chrome sleeve that the handle rides on is somewhat adjustable. That acts as a stop also for the handle on the Moentrol. If the diverter sticks too far out and that sleeve is all the way against the diverter, the handle will just spin.

Hey good job anyway.

They came along way in the stops. I never took the newer ones apart. Its good info. I remember just stem and washers, then they came out with 1/4 turns. Now this check stops....Hmmmm.

Mike NJ
 
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Old 06-27-11, 07:39 PM
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Welllll... this valve body ain't gonna pull ! I absolutely garonteee you that! If I gorilla the screws, the escutcheon is gonna bend before that valve moves! I mounted a 1x3 between the studs and used the four screw holes in the valve to secure it to the 1x3... solid as a rock. I absolutely detest valves and pipes that wiggle around inside the wall.

I'm sure there is some 'fudge' built into the design, and the biggest problem is the cheesy comic books that they call installation instructions. Can you imagine if BOILERS came with such crappy instructions? Dang we would be busy!

I'm going up now to move it back into the wall 3/8"... maybe by the weekend I'll have the rest of the cement board up and ready to move on to the next phase.
 
 

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