Dave
Dave, Your pipesizing is too small. 1/2 to upper floors should be 3/4. If the supply from the main is poor have the water authority rectify the pipe. You may be responsible for main to meter connection so check with them. Correct pipe size is an art. Depends on pressure and flow rate from watermain. It may mean you need 1 pipe. As I said check with water supplier or a local plumber.
