We are remodeling a bathroom that was originally installed in the 20's. It had all old copper piping done in some weird ways. The bathtub's piping has been replaced already and pretty easily using pvc and qwest piping. However the toilet and the sink are not cooperating. The valves have to be replaced and we have tried everything we can think of to no avail. I don't know very much about plumbing but I can tell you this: at the toilet, instead of coming from the wall, the pipe and valve run straight up to the toilet from the fllor. Because it did not match specifications for the toilet, the top part of the pipe including the valve had to be removed down to the first connection under the floor. Everything we have used to replace this has not worked. It is either too big or too small. We use these things that look like small hoses and are flexible. This is what Home Depot has suggested everytime. Whenever we tell him that they are wrong, they just sell us another piece of crap that doesn't work. Are we doing something wrong with the piece (forgive me, I am blonde) or do we have to use something else. My boyfriend says that maybe we just need to repace it with more copper piping but I am afraid we will just get into another mess. Please help me!!!

 

You can use PVC for cold water and drains only. You can't use PVC for hot water lines.
You can use compression fittings to transition from copper to PVC or CPVC.
Here is an illustrated article from Reader's Digest "The Family Handyman" magazine on converting to CPVC that should help you:
http://www.familyhandyman.com/200007/cpvc/main.html
Good Luck!
Mike