I went to the local Home Depot to get all the things that I needed to install new copper piping to my new shower/tub valve I bought yesterday. Told the guy what I was doing, showed him my sketch, and he happily sold me 20 feet of 1/2" copper tubing with the neccesary couplings. I mentioned to him in the store that I was amazed that the stuff in the rolls was 4x more expensive than the rigid 1/2" that he sold me. He smirkily said "yeah, isn't that something?"
When I got home I researched the difference, and found that he had sold me 1/2" M rated copper (under $5 per 10 feet), versus the other 1/2" L rated ($20+ for 10 feet) that I had noticed. The sites that I read online about the stuff say to only use the thin wall (M) for vents and other "light duty" piping, and to use medium wall (L) for water supplies.
So am I out the money I spent on the M piping, since I already cut the stuff? This is a house that I'm finishing up to sell next month, but I would hate to think that the new owner is going to have problems soon after... What are your thoughts on using the M rated copper on supply lines to the shower/tub valve and the lines from the valve into the showerhead/tub spout?
Oh, and I checked the copper that was already in the walls of this 21 year-old house that has never had a leak. You guessed it... M rated. Hence, my dilemma :-)