Before You Begin
Measure the height and width of your pet to choose an appropriate size door. Most pet doors have a flexible flap that your favorite pet pushes to get through and a lockout slide to keep the passage closed. The better grade models have weather-stripping and magnetic locks that hold the door shut. You'll also find pet doors designed to be installed in a screen or sliding patio door, which are installed in basically the same way.
Here are some typical sizes with opening dimensions of how pet doors are sold.
- Small 5"wide by 8" high
- Medium 7" wide by 11" high
- Large 9" wide by 15" high
- Extra Large 10" wide by 15" high
- Super Large 15" wide by 20" high
When you know the size door that fits your pet, make a preliminary sketch of its dimensions on the door using a light pencil mark. Position the pet door so it's in the center of the door and a few inches above the door's bottom. Use this as a guide for locating the paper layout template that comes with the door.
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Step 1 : Place the door on a work surface
Remove the door from its hinges with a hammer and screwdriver. Put the blade of the screwdriver under the top of the hinge pin and use the hammer to gently tap it upwards. Pull out the hinge pins in this way and carefully pull the door away from the hinge installed on the door jamb. Then lay the door flat on a pair of saw horses with its inside face up so the door is easy to work on.
Step 2 : Tape the template
Make a few careful measurements to be sure that the paper layout template included with the door is correctly positioned. Then tape it to the door. The bottom of the pet door should be parallel with the bottom of the door and at least 2 inches above the bottom edge.
Step 3 : Bore and cut the corner holes
Bore a 1/2-inch hole at each corner of the template so you'll have a starting point to begin cutting through the door. Use a saber or keyhole saw to cut from hole to hole. After you cut three sides of the opening, apply a piece of masking tape that spans the cutout and the door to support the scrap piece as you near the end of the cut.
Step 4 : Fasten the frame of the pet door
Hold the frame of the pet door in place and then drill the pilot holes for its mounting screws provided by the manufacturer. Then fasten the pet door using the screws provided with it.
If your pet resists using the new pet door, open the flap door and tape it so it stays open. After a few days lower the flap so it's half-open and half-closed. Gradually your pet will get the idea that pushing the flap opens it.