How to Relocate a Kitchen Sink

D Plumbing, specifically moving a sink, represents one of the most challenging layout changes in a kitchen. You are shifting the heartbeat of the room, which requires not only brute force to cut through flooring and cabinetry but also a precise understanding of drainage gravity and pipe venting. When done correctly, the new sink sits exactly where you need it with zero leaks and a drain that flows as fast as the old one. Before you start tearing out the subfloor, ensure you have a clear path for the new plumbing runs. The biggest mistake is failing to account for the drain's slope, which must drop at least 1/4 inch per foot. If you cannot achieve this pitch to reach your main stack, you will deal with constant clogs. Success here is measured by the silence of your pipes and the speed of your drainage.

  1. Kill the Water First. Locate the main water shut-off for the kitchen and close it. Open the existing faucet to bleed pressure, then disconnect the supply lines and the P-trap to clear remaining water.
  2. Cut Your Access Holes. Expose the studs and joists by removing drywall or cabinet backs as necessary. Use a reciprocating saw to cut access holes, taking care to avoid nicking existing electrical wires.
  3. Run Supply Lines Now. Route PEX tubing from the original supply stubs to the new sink location. Use copper-to-PEX adapters if your house has existing rigid copper pipes, and secure all lines to studs with pipe clamps.
  4. Nail the Grade—Literally. Connect ABS or PVC pipe to your existing sanitary tee. Ensure a consistent downward slope of 1/4 inch per foot toward the main stack, and use sweeping 90-degree elbows rather than sharp 90s to prevent clogs.
  5. Breathe Life Into Drainage. If the new location is far from the original, you must extend the venting system to prevent the trap from siphoning. Run a vent pipe from your new drain assembly up to the main stack or an attic vent.
  6. Hunt Every Last Leak. Turn the water back on slowly and check every joint for leaks. Leave the walls open for at least 24 hours to monitor for slow drips before patching the drywall.