Getting a snug fit for my shower faucet

[rdavison39]

Hi there - i'm renovating my bathroom and bought a shower fixture that has a shower/rain head diverter. While the main controls have a plate that fits over the main controls and onto the tile nicely covering the holes, the diverter is a separate valve and has a very small flange (2") with a female thread. I have a brass nipple valve (male) that protudes from the wall that the diverter would screw into, but what this means is that i have to have the nipple value the exact distance protuding from the wall taking into account the wall board and tile. I can buy different length nipple valves but they seem to only come in 1/2 length - and the precision i'd have to have is probably in the neighbourhood of 1/16 to 1/8 inch. That is, if i don't leave enough thread exposed i won't get a tight fit and possibly risk breaking the tile if i screw it tight - if i leave too much thread exposed i'll have a gap between the flange on the diverter.

This has to be a common problem people face with a common problem. One thought of mine is to plumb the copper behind the cement board such that it has some "spring" to it. That is, don't fasten it down that way when you tighten it up, it has some give. Just guessing here and any ideas or confirmation of this idea would be great

Thx in advance
Ron

 

[Jadnashua]

Some places can make a custom brass nipple in whatever length you want, but that can be problematic as well since there would likely be slight differences in the tap verses another, and therefore how tight it needed to be to seal. You might use a piece of copper with threaded adapters soldered on each end if you have enough room. If you have access from behind, you could put the blocking up after you got it tight. A hole in drywall might be easier to fix.

 

[Sponsor]

 

[LLigetfa]

Yes, I've experienced the same issue putting in a wall union for a hand shower. The first time I ended up a tad too long and had to grind a little off the threads to get one more turn to close the gap. The next time I planned for it and I drilled a few holes in the wood bracket so it would have enough flex in it and made sure I wasn't on the long side.

 

[Terry]

I will answer for the plumbers here.
1/2" increments is fine. There is enough plus or minus depending on how tight you turn it.
We've been doing it that way for decades. It helps to have plumber arms. Sometimes you need them.

You do want to start from scratch though, with both ends doped, taped and/or both and loose.
Then you decide whether to go soft or hard on the turns.

 

[hj]

If by "diverter" you mean the valve that changes the flow from one attachment to the other, I have never heard of one that uses a 1/2" pipe to secure the flange, and if it does, and you are referring to the correct piece, it would not have to be "tight" since there is no water at that point.