Cast iron alcove tub on slab - waste and overflow tips?

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As soon as I posted that, a solution occurred to me. This combinations of adapters and elbows would get the drop-ear elbow almost to exactly the right position, i think. It would also let me attach the spout directly to the drop-ear and support that with something strong, which i was worried about because the spout is pretty long and heavy. Is this kosher?

redlands-04.jpg


Even if it would work, I'd be happy to hear about better solutions too.
 
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Well, upon further investigation, the spout is going to have to be way too close to the valve for any sort of copper configuration that I can think of that isn't a total rube golberg affair.

the top of the drop ear elbow needs to be about an inch below and and inch in front of the bottom of the female adapter on the bottom of the valve. Like this:

redlands-03.jpg


All that stuff behind the drop ear in that photo is just there to hold the elbow in the correct position with relation to what will be the finished surface of the tile wall.

At this point, i am very inclined to just get a couple of sharkbite fittings and make that connection with a small loop of pex. Thoughts?

Thanks! Sorry for so many posts.
 

Tuttles Revenge

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For a spout that long, I like to have my drop ear as far back in the wall as possible for one point of anchor, then another at the wall rest on / shim if needed. But, being that its Male threads, you would need a coupling on the end of a nipple to connect that up. No matter which way you do it, your finish better be dead on as you will have little play in the threads to make tiny adjustments. Tho, The spout should have some play on the o-ring shaft correct?
 
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For a spout that long, I like to have my drop ear as far back in the wall as possible for one point of anchor, then another at the wall rest on / shim if needed. But, being that its Male threads, you would need a coupling on the end of a nipple to connect that up. No matter which way you do it, your finish better be dead on as you will have little play in the threads to make tiny adjustments. Tho, The spout should have some play on the o-ring shaft correct?

Man, there's zero play. The groove you see behind the o-ring in that picture of the coupling is where the hex-head set screws in the billet spout hold the flange. Sets in one position, and that's it, so, yeah...no room for error.

And aside from a similar rectangular loop of copper elbows sweated together, I don't see an alternative to the loop of pex. I was thinking of actually using a piece of steel angle to secure the drop ear elbow...i do a lot more fabricating with steel than carpentry, and what i'd rig up would be very secure.

I just don't know if there's any problem with the whole loop idea...seems there wouldn't be. I've never used pex, but it seems the best solution here too, since i can't imagine a way to make the last sweat in the loop of elbows without everything attached to the framing and the valve, which i'd really rather not do, since i'm a rank amateur and would probably melt the valve innards. ha!
 
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of course, now that i've run to the big box and got the PEX, i see that it doesn't really want to make that 3-inch radius turn i'd hoped for without the bend supports that i don't have. so, returning to the copper idea, i've got this, which at 10 sweats, seems pretty high on the jank meter:

redlands-02.jpg


Ha!

I guess it doesn't look a lot jankier than the stuff i took out, so there's that...
 
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this configuration has only 8 sweated joints, so it's a little less janky.

redlands-01.jpg


Man, i don't know what I'd do if i was actually a plumber. I'd go broke trying trying to figure this stuff out. :)
 

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There are brass 1/2" MIP x 1/2" FIP extensions that net out to around 1", although maybe it would be too difficult to find one that provides the correct extension.

Or you might be able to use a C X C drop ear elbow with a FTG x FIP copper female adapter.

Cheers, Wayne
 
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There are brass 1/2" MIP x 1/2" FIP extensions that net out to around 1", although maybe it would be too difficult to find one that provides the correct extension.

Or you might be able to use a C X C drop ear elbow with a FTG x FIP copper female adapter.

Cheers, Wayne

Neither of these options had occurred to me, but I'll look into both of them. Thanks! The c x c drop ear looks like it might be about a half inch too long at its minimum, but I don't have one handy so I'll get one and have a look.
 

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If I'm reading Nibco's catalog correctly, a standard drop ear CxF 1/2" elbow has a projection from the C centerline of 27/32".

A C x C drop ear elbow has a projection from the C centerline to the base of the solder cup of 7/16"; and a FTG x F female adapter has a total length of 1-7/16". So together the projection from C centerline would be 1-7/8", or +1-1/32" from the CxF drop ear elbow.

Of course, that gives you a wrought FIP end instead of a cast FIP end, so the takeup of your MIP end when making up the threaded connection may differ a little, easily +/- 1/32".

They do also show a C x F cast straight adapter with ears, with a projection to bottom of solder cup of 3/4" (versus 27/32" for a wrought adapter without ears). Then a C x Ftg elbow has a projection of 31/32" from the cup centerline, for a total projection of 1-23/32", or +7/8" relative to the CxF drop ear elbow.

Cheers, Wayne
 
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That's very helpful. The centerline of the copper dropping from the valve is 1 15/16" (1-3/16 (centerline to back of backerboard) + 12/16 (thickness of backerboard and subway tile)) from where i need the coupling and flange to be when everything is snugged up if they're going to be flush. It sounds like one of those combinations may work.

This being a section of plumbing that will never be pressurized (i'm a little nervous about the sharkbite fittings in the wall), i almost feel like i should eliminate as much potential for error as possible and use the pex and sharkbite fittings, which would allow foolproof, precise positioning of the drop ear elbow. I'll keep thinking on it! Thanks, very much, for the math and ideas!
 

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This being a section of plumbing that will never be pressurized
That's not quite the case. Instead the numbers might work out like this (all made up for an example):

Say your static pressure at the shower valve is 60 psi, and when you turn on your tub spout, you get 8 gpm out. The pressure at the end of the tub spout (falling water) is 0 psi. The pressure at the inlet to the shower valve might be 50 psi (10 psi frictional loss between the water main and the shower valve); at the outlet of the shower valve it might be 35 psi (15 psi frictional loss within the shower valve); maybe at the threaded rough outlet it is 20 psi (15 psi frictional loss on the parts you are currently working on); and then the tub spout itself loses 20 psi while flowing 8 gpm.

Not sure of the proper ratios of the above sources of pressure loss, those are just guesses. The point is that the connection from the shower valve to the tub spout will be pressurized, just not at full water pressure.

Cheers, Wayne
 

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What about the tolerances of the shower valve itself? Could it be moved forward in line with the tub Elbow?
 
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That's not quite the case. Instead the numbers might work out like this (all made up for an example):

The point is that the connection from the shower valve to the tub spout will be pressurized, just not at full water pressure.

Cheers, Wayne

That's correct, for sure. And the coupling for the spout increases the pressure somewhat over what it might have been on a "normal" spout because it chokes down to a mere 1/4 inch ID. I guess i am thinking more along the lines of "it's only pressurized when the tub is being filled, not when I'm laying in bed, wondering if it's dripping in the wall under constant pressure." ha! kind of like i do now, wondering about the sharkbite end caps that are temporarily capping the lines while i figure all this out. it's actually ingenious technology. i shouldn't be afraid of it.
 
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What about the tolerances of the shower valve itself? Could it be moved forward in line with the tub Elbow?

This is actually the only reason i'd even entertain doing this with copper as an amateur. The valve's tolerances are 1/2 inch. (2 1/2" to 3" from the back of the valve to the finished wall surface). I have it set up now for the plastic case to sit flush with the finished wall, but could actually mount it up to 1/2 inch deeper if needed. I figure if i go with copper, i'll do the math assuming I'm mounting the valve in the middle of the 1/2 inch tolerance, then have 1/4 inch either way to correct for bad design.
 

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This is actually the only reason i'd even entertain doing this with copper as an amateur. The valve's tolerances are 1/2 inch. (2 1/2" to 3" from the back of the valve to the finished wall surface). I have it set up now for the plastic case to sit flush with the finished wall, but could actually mount it up to 1/2 inch deeper if needed. I figure if i go with copper, i'll do the math assuming I'm mounting the valve in the middle of the 1/2 inch tolerance, then have 1/4 inch either way to correct for bad design.

Was hoping for more and be able to line up the valve opening to the tub drop ear. Are you married to the tub spout? Maybe a different fixture there will save you a Lot of headache.

Could you increase the height of the valve to give you more room between the spout and more options in your fitting choices?

On tight tolerance valves, I like to place the minimum mark out to the point where my backer and tile are with the thinnest possible mud (7/8" is my rule of thumb).. a point you know you can't cross because you can't get thinner.. that gives you the maximum room for play in your tile / mud etc.
 
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This Hansgrohe looks similar to me and has a much easier isntallation IMO.

Wow, they certainly have given a lot more thought to the poor bastard who has to install the spout than Inolav has...a much smarter system.

I have so much time and thought into this one, though, that it's almost a matter of pride to figure it out. I also have the spout in my possession already, and all the other hardware in both bathrooms is also Inolav. It shouldn't matter, but i expect to live in this house forever, and i'd feel like i compromised every time i saw the non-Inolav spout. :) I have a lot of time to screw up and correct my mistakes too, since we have a second bathroom.

I could definitely raise the valve. The only reason i'm putting it where it is is because that's the "standard" and I assume at some point, you make it hard to reach when seated in the tub. How far would you deviate from standard? As it is, the spout is 6 inches above the tub (at wife's request, for potential hair washing convenience) and the center of the valve is 6 inches above that. the tub is 14 inches tall, so it's shallow, making the valve about 24 inches above the bottom of the tub, as currently configured.
 

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When customers ask what the Standard Height of something is.. I tell them its whatever they want. I install all tub/shower controls at 36-48 inches. What I call Handshake level. If the tub/shower is intended to be used primarily as a shower, then I suggest comfort in that position over all other functions. I would raise not only to give yourself a bit more wiggle room, but to make it more comfortable

Since you also also already have the spout you intend to use, thread the adapter into one or both threaded elbows you have, Install the stub out in the spout and tighten it snug. then you can measure the distance from the back of the escutcheon/finished wall to the back of the drop ear/threaded elbow.
 
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When customers ask what the Standard Height of something is.. I tell them its whatever they want. I install all tub/shower controls at 36-48 inches. What I call Handshake level. If the tub/shower is intended to be used primarily as a shower, then I suggest comfort in that position over all other functions. I would raise not only to give yourself a bit more wiggle room, but to make it more comfortable

Since you also also already have the spout you intend to use, thread the adapter into one or both threaded elbows you have, Install the stub out in the spout and tighten it snug. then you can measure the distance from the back of the escutcheon/finished wall to the back of the drop ear/threaded elbow.

You know, it never occurred to me for a minute that I could do this, and it kind of changes everything. We'll be using this for showers way, way more often than baths, so it makes total sense to move the valve up. It would only be a few inches I'd need to make that run totally reasonable for PEX, giving me the freedom to very carefully mount the drop ear elbow exactly where it should be. I think I'll go that route.

Thanks a ton. Really helpful to hear it from someone who knows what they're doing.
 
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