How to Make a Cat Flap for a French Door

If you have French doors, you don't have much room to install a flap for your cat to get in and out of your home. If your French door has small glass panes with window trim called mulls, you can remove one section of glass from the French door and install a flap for your cat. This solution will allow your cat easy access both ways.

Things You'll Need

  • Putty knife
  • Hammer
  • Tape measure
  • Utility knife
  • 1/4-inch thick rubber sheet
  • 1/4-inch diameter by 1/2-inch long wood screws
  • Screwdriver
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Instructions

    • 1

      Select a pane of glass at the bottom of one French door. In many cases, the door will have rows of three windowpanes. Select any one that suits you.

    • 2

      Wedge a putty knife between the wooden mull at the top of the windowpane and the glass. Tap the putty knife with a hammer, and then pry the mull off the door. The windowpane has a horizontal mull at the top of the pane and one at the bottom. It also has a vertical mull at the right and left side of the pane. Pry off all four.

    • 3

      Pull any nails out that stuck in the door after you removed the mulls, with the claw end of a hammer.

    • 4

      Pull the glass pane out of the window, and store it in case you ever want to reinstall it. Store the mulls with the glass.

    • 5

      Measure the height and width of the opening. Add 1/2 inch to the height, so you can secure the flap to the door.

    • 6

      Cut a piece of 1/4-inch rubber to match these measurements, with a utility knife. A mud flap from an automotive part supplier works well for this, since it's pliable.

    • 7

      Place the top edge of the flap over the spot where the top horizontal mull mounted, and then secure the flap with four evenly spaced 1/4-inch diameter by 1/2-inch long wood screws.