Adapting plumbing to accommodate a pedestal sink requires extending the copper water supply pipes and lengthening the original steel drain pipe using PVC pipe and transition couplings. This project may require a substantial amount of time in addition to familiarity with a soldering iron.
The first step is to cut open the section of the wall where the new pedestal sink will be installed in order to access the original drain pipe and copper water supply pipes. Then, connect the new PVC pipe to the original steel drain pipe using the transition couplings. Transition couplings are loops of steel that surround a circle of rubber called a "gasket." The steel loop can then be tightened using screws to seal the PVC pipe and the original steel drain pipe together. Once the first portion of the PVC pipe has been connected to the original drain pipe, new sections of PVC can then be fitted together in order to extend the drain pipe to the desired height of the pedestal sink. The new sections of PVC pipe should be fitted together using glue. Once this height is reached, use a PVC elbow to turn the drain so it extends from the wall and can be connected to the bottom portion of the sink.
For the copper water supply pipes, solder on the additional copper sections of pipe until the desired height is reached. Then, solder copper sections horizontally to extend the pipes at least 6 inches from the wall. These will be attached to the water shut-off valves. Once the drain and copper water supply pipes are at the desired height, the new pedestal sink can be installed. Make sure to board up the wall cavity where the new plumbing is located with a piece of drywall before installing the pedestal sink.