Strictly speaking, this isn't part of the tile job. Since I was going to be opening up the walls, I planned to replace the tub/shower combo water controls. 

The current controls were probably the originals from when the house was built 30-40 years ago. There are separate hot and cold knobs and a third knob to control diversion from the tub to the shower head. I don't know if it was the best they could reasonably do when they installed it, but those separate hot and cold controls are totally un-hip. Long ago, I replaced all of the sink faucets with single-handle models. The other problem is that the controls have the old school rubber washer mechanism to prevent leakage. I'll be glad to get rid of that failure point.

Every big box home center has a dizzying collection of tub/shower combo controls on display. Online options also add significantly to the dizziness. My requirements are humble:

• Brushed nickel finish
• Guts of ceramic or brass or whatever ... no rubber washers
• Single handle for temperature control
• Low price (I hoped to stay under US$100, but was willing to stretch to US$150)
• Integrated stop valves
• A hazy and subjective thought about the ease of working with it as part of my tile job

Integrated stop valves are screwdriver-operated shut-offs for the hot and cold water supplies that are part of the unit itself and hidden behind the trim plate. If you have to do work on the control, you can shut off the water supply locally instead of needing to turn off the water to the entire house. I don't know why all of the manufacturers don't include this on most of their models, but they don't. Having it on my requirements list significantly narrowed my choices (which was OK since the glut of choices was driving me a little crazy anyhow).

After studying a lot of product descriptions and installation manuals, I settled on this Glacier Bay house brand model from Home Depot:

I had to decide whether to install this myself or bring in a real plumber to do it. I've done plenty of little plumbing jobs around the house over the years, but this was a little different. Being behind a tiled wall, any faults could get to the point of doing a lot of mischief before being discovered. My plumbing soldering skills are so-so. I really like these modern push-to-connect plumbing fittings, but I agree with the skeptics in being leery of using them in closed-up locations. 

I decided to evaluate my soldering skills since it has been a few years since I last tried it. I took some scrap copper pipe and some inexpensive fittings and soldered them up. They didn't turn out to be the prettiest work (the flux got a little bit out of control), but they seemed to be water tight as far as I could examine and test them.

I do plan to temporarily use a couple of push-to-connect caps on the supply lines in order to minimize the time I have to turn off the water to the whole house. After I cut out the old fixtures, I'll cap those lines so that I can fool around with the new stuff at my leisure until it's time to make those last two supply connections.

One last detail about fixtures. Our household customer service department has received complaints that the shower head is mounted too low. As far as I can tell, it's mounted at a fairly standard location, although some inches lower than the other shower head in our house. I plan to boost it upwards by 6-8 inches to keep the natives happy.