How to Replace the Floor in the Cabinet Under the Kitchen Sink

Robin Hewitt

Leaking pipes and defective drains are part and parcel of being a homeowner, and if not found immediately can cause damage to the floor of the cabinet in which the water source is located.

Working under the sink is working in cramped quarters.

If you’ve recently found and repaired a water leak in your home, you may be left wondering how to repair the damaged floor in the cabinet under the faulty sink. You’ll be pleased to learn there’s a set process for this repair, and it can be performed with a minimum of time and tools.

  1. Turn off the water supply and disconnect the water and drain pipes located beneath the sink.

  2. Measure the width and depth of the cabinet floor as well as the pipe openings.

  3. Transfer the measurements to a piece of 1/2 inch plywood, taking care to check all measurements for accuracy.

  4. Cut the plywood, using a circular saw for the outside cuts and a jig saw for the pipe opening cuts.

  5. Remove the existing floor of the cabinet by cutting two inches in from the front, back and sides with a jig saw. You will now have an opening that exposes the subfloor below, with a two-inch lip around the parameter of the cabinet floor.

  6. Place the new flooring piece directly onto the two inch lip on the bottom of the cabinet, over the exposed pipes.

  7. Screw the new floor into place, using one-inch wood screws to fasten the new floor securely to the two-inch framework.

  8. Reconnect the pipes and turn on the water supply, checking all connections for leaks and tightening as needed to provide dry connections.


The new floor may be painted or covered with contact or shelf paper to match the existing cabinets. It’s a good idea to install new water lines while this project is being completed.


Always wear hand and eye protection when using power tools.