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How to Shorten a Door

How to Shorten a Door. When you install new flooring that raises the level of the floor, if your interior doors do not have enough clearance they will drag against the floor. When this happens the door must be shortened by cutting off the bottom of the door.

Pre-Cutting Steps

  1. Determine whether your door is solid or hollow. Hollow doors require an additional step, since the bottom may end up being cut off.

  2. Mark the clearance needed on the door. Allow for a 1/4-inch to 1/2-inch gap.

  3. Pull out the hinge pins on the door.

  4. Use a blanket (or other padding) to cover your cutting surface, typically a sawhorse.

  5. Rest the door on the sawhorses.

  6. Draw the cutting line on the front and edges with a pencil.

  7. Apply a strip of masking tape along the line to protect the finish and reduce splintering.

  8. Clamp a metal straightedge, such as a framing square, along the line to be cut.

Cutting and Trimming Steps

  1. Cut along the line with a utility knife to score the door. Cut through the tape and into the door. Make a few passes.

  2. Use a circular saw or hand saw. Make sure the saw blade is sharp and has at least 18 teeth.

  3. Remove the metal straightedge.

  4. Clamp a straight 1x4 or 1x6 board to the door to act as guide for the saw. Position the board so the blade will cut about 1/32-inch to the outside of the cutting line.

  5. Guide the saw along the board to trim down the door.

  6. Remove the clamp, board and masking tape.

  7. Hang the door. Swing it completely open and closed on its hinges. If the door still rubs against the floor, lay a pencil flat on the floor and run the tip along the face to mark a line.

  8. Trim below the new line.

Finishing Steps

  1. Sand the edge of a solid door gently with a sanding block.

  2. Retrieve the scrap that was cut from the bottom of a hollow door. Separate the bottom piece of the door from the panel with a utility knife.

  3. Coat both sides of the piece with a heavy duty wood glue. Slide the piece into the opening. Clamp the edge of the door until the glue dries.

  4. Hang the door and put the hinge pins back in place.