You said "Were it my home, there would be continuous piping in the stud bay, no joints of any kind." Interesting point, but one the other hand, the purpose of placing he lines in the outside wall is to supply water to a shower mixer that is installed in that wall. Regardless of what piping material the customer chooses you still have joints where the supply lines attach to the mixer. If it were not for the mixer in that wall, there would really be no necessity to run any water lines through that wall. There is another point that none of us have mentioned. Generally, although not always true, the outside wall is the back wall of a shower. Code prohibits installing a shower where the shower head points toward the door of the shower, so in most instances we would have no need to install the mixer in the outside wall. I would agree that in some regions they have a lot of problems with copper as a result of acidic water, but here again, that is not common to all location and even if the water quality is an issue, if the structure is supplied from a municipal water supply federal mandates require the municipal water supplier to treat the water, therefore the problem is generally only prevalent on private well water supplies. Far too often the problem of pinholes in copper pipe is not a fault of the water, but rather, it is a fault of the installer because they installed undersized pipes. If the pipe is undersized the velocity of flow through that pipe exceeds the code maximum of 8ft/sec and the pinholes are actually a result of pipe wall erosion caused by excessive velocity. This is especially problamatic in DIY renovations where they upgrade the showers to multiple shower heads, but do not increase the size of the pipes appropriately to handle the additional load. Many will argue that copper only has a 15 to 20yr lifespan but in my region nearly all the homes that were constructed in the late 40's and early 50's were constructed with type M thinwall copper and 50/50 tin/lead solder, yet we rarely see any problems with that pipe other than the occassional frozen water line or a break that results from some form of mechanical stress. On the other hand, currently the trend is to use Medium wall copper and 95/5 lead free solder, which produces a much harder joint and in some critical locations where gaining access later might prove a problem I often use heavy wall copper and braze the joints, or I run medium wall continuous roll copper to eliminate joints in that area. Here again, some will argue that PEX would be a better choice, but knowing that rodents of all varieties, I.E. rats, mice, rabbits and Opossums all seem to have a sweet tooth for PEX I am a bit reluctant to use PEX in this application. I can assure you from first hand experience, when a mouse chews a hole through PEX it makes a pinhole in copper seem like childs play. Cutting to the bottom line, after years in the trade I think Alponse, Brickeye or myself could go on for hours relating the horror stories of leaks in an inaccessible location but statistically speaking, no matter what type of pipe you install, if it is installed correctly the individual homeowners risk of catastrophic failure is very slight.

I haven’t met a contractor yet who doesn’t do things they know they shouldn’t. There’s no need to be rude, and respond the way several people did. Never trust a contractor- always verify- you could call your local building department and verify with them. What are the people’s qualifications on here that responded? A moisture resistant board such as durock isn’t waterproof, it’s water resistant, and works in combination with other components to prevent moisture from penetrating walls. All of the components rely on proper installation by the professionals which you can never rely on. They all think they can skip steps and do it “their way” and they always have a “it’s fine” response ready and waiting when you point out they aren’t following code, manufacturers instructions or industry standards. Never trust a contractor.

Excellent! Is a pry bar the same as a crow bar? We will need to chisel away at the grout first, so I trust the chiseling will be gentle enough not to damage the shower we are keeping? Thanks for you feedback, aliceinwonderland_id

I did not read many posts. Did anyone comment that your tiles look like there is a lavender cast to them? I see that especially when you have it up against some of the greenish grays above, like the "Light Pewter". It is not the direction I would take the paint. If you go with blackish vanity be sure it is not a greenish black, but one with more purple in the undertones, IMHO. I think the navy with a bit on the reddish side would look nice, not a tealish navy, again IMHO. with the walls I'd try a very light, white rendition of the vanity color. I think it will need to have a hint of lavender.