Removing the P-trap connected to a pedestal sink requires some care and planning. In the majority of cases, if the pedestal has been originally installed properly, this will require removing the pedestal. Most pedestal sinks depend upon the pedestal for a certain amount of support. Still, since the sink itself is fastened to the wall, the pedestal may be removed for brief periods of time if necessary to work on the P-trap.
Things You'll Need
2 x 4 board
Check to confirm the sink is tightly fastened to the wall. Look up and underneath the sink to check for the fasteners, or mounting bolts, that hold the sink to the wall. You should see the heads of two lag screws, or two nuts, at opposite sides of the sink against the wall. These fasteners will go through holes or slots on the back, underside of the sink. Use the adjustable wrench to check the tightness of these fasteners. They must be tight before continuing.
Look into the opening at the backside of the pedestal. Find the heads of the lag screws that go through the pedestal base to secure it to the floor. Use the wrench to remove these lags.
Measure the height of the pedestal and cut the 2 x 4 to the same length.
Slide the pedestal away from the wall and out from under the sink. Have a helper hold the outer edge of the sink and gently lift up very slightly so the pedestal will slide freely outward.
Position the 2 x 4 upright under the sink in place of the pedestal to support the sink while removing the P-trap.
Place the bucket beneath the P-trap and use the pipe wrench to loosen the large nut just below the sink tailpiece. The tailpiece is the pipe that sticks straight down from the center of the sink.
Loosen the nut on the other side of the P-trap.
Pull down on the trap to remove it.
If the pedestal fits into a notch or groove where the sink rests on it, loosen the sink mounting bolts at the wall slightly to gain enough movement so the sink can be raised slightly to allow the pedestal to slide out from below it.
Do not over tighten mounting bolts as this can crack porcelain.