Concealed water piping system seems to be very popular for a very long time. But, after just about 20 years of usage, concealed piping is giving so many problems that I wish it was surface piping from the start.
I broke open the plaster and found a serious leak. I have no choice but to repair it. At the meantime, I applied a temporary fix.
It seems that even with copper tubing, it won't last more than 20 years. Problems started appearing so many years ago and now, my house is full of patches due to leaky pipe.
So, if ever, I will never use conceal piping again. It is simply too problematic. Not worth the trouble!
There is another leak under the bathtub and that would be my next repair work!
If you are in the United States and would need brass compression fitting, you may try Gruner.