Dragon Pet Door For Doors - Installation Instructions

Installation Instructions


  • Flap and Frame Assembly
  • 4 Long Frame Screws - 2 ¼" long 10-24 machine screws
  • 4 Short Frame Screws - 1 ¾" long 10-24 machine screws
  • 4 Frame Nuts - serrated flange 10-24 hex nuts
  • 4 Frame Washers - steel 9/16" washers
  • 1 Locking Cover - rectangular sheet with a hole near the top


Required Tools: Phillips screwdriver, electric drill, 5/16” or 3/8“ drill bit, jigsaw, painter’s tape, pencil.  

Optional Tools: Flathead screwdriver, 3/8” socket or wrench, pliers.



Step 1: If possible, remove the door from its hinges using a flathead screwdriver and hammer to tap out the hinge pins. Lay the door flat for installation. Tape these instructions (they double as a template) to the door where you want to install, this face up.

a. The top edge of the template should be at least 1 ¼” (3,2 cm) above the dog’s shoulders.

b. The bottom edge of the template should be at least 3" from the bottom of the door to maintain the door’s strength. Level the top edge of the cut-out line.

c. Level the top edge. 

Step 2: Mark the physical outline of this template with a sharp pencil. Remove this template from the door. With a 5/16th (8mm) or or 3/8” (9,5 mm) drill bit, 5/16” preferred, drill through the corners of the outline with the tip of the bit directly on the outline’s corners. Make sure your drill is kept level and that it drills all the way through the door. 

Step 3: Place your jigsaw into the holes and cut along the lines you drew in Step 3. You should be making a rectangle connecting the center of each of the holes. Cut as straight as possible; aim to not deviate more than 1/8” from the line on either side.



If you have a single flap unit, the frame with the flaps installed goes on the inside of your house. If you have a double flap, it does not matter which one goes on the inside or which goes on the outside of your house.

Step 4: Test fit the frame tunnels. 

a. Lay the inside frame face down on the floor.

b. Fit the outside frame into the inside frame by first placing the bottom of the outside frame’s tunnel into the bottom-left slot of the inside frame’s tunnel. Next, place the right side of the outside frame’s tunnel into the top-right slot of the inside frame’s tunnel (pictures below show the slots and frame orientation).

c. Remove the frames from each other once you are familiar with how they fit together.


Note: there is only one way that the frames fit together. If you need to force it then it is the wrong way. 

Step 5: there is only one way that the frames fit together. If you need to force it then it is the wrong way. 

a. At least one of the four locator posts (small posts extending from the bottom of the frame) should meet the bottom of the cutout, depending on the evenness of the cut. 

Note: If the rough cutout is slightly too, you will need to raise the frame to avoid any gaps and the locator posts will no longer be on the bottom of the cutout. 

b. Use painter's tape to temporarily hold the inside frame around the door. Place tape all around the frame, tightly adhering it to the frame. 

c. Ensure that the screw holes in the frame are all visible through the cutout opening.


Step 6: Fit the outside frame into the inside frame like in step 4. You may need to hold the inside frame to keep it from being pushed out of the door. 

a. Fit together until both frames are flush with the door. The locator posts of the outside frame do not have to be in contact with the rough cutout.

b. Use painter’s tape to temporarily hold the outside frame in the door.

c. If the frames fall out or move around too much while fitting them together, remove all tape and go back to the beginning of step 3.

Step 7: Fasten the frames to each other. Make sure to read through every part of this section before starting.

If your door is 1 ¾” thick, use the longer 2 ¼” screws provided. If it is 1 ⅜” thick, use the shorter 1 ¾” screws provided.

DO NOT overtighten screws. Tighten just enough for the frames to sit sturdily flush with the door.

a. Place a steel washer onto a frame screw (the 2 ¼” or 1 ¾” screws) and place into one of the four frame screw openings from the inside frame to the outside frame. The inside frame should have the screw head. 

Dragon door mount screws

b. Thread a flanged nut onto the screw by hand, reaching through the frames or around the door. You do not need a washer under the nut. The nut should be on the outside frame. Tighten down with a Phillips-head screwdriver.

Note: For maximum ease, press the nut into the frame as you tighten it. This lets the serrations bite into the frame so you don’t have to grip the nut directly. If your nut spins around too much as you tighten despite the serrations, a ⅜” hex socket bit, thin wrench, pliers, or vice grips can be used to hold the nut.

c. Repeat for all four screws.

Step 8: At this point, there should be a washer visible on the inside frame and a nut visible on the outside frame at each of the four points. 

a. Remove the tape holding the frames to the door.

b. If the frame positions need to be adjusted, loosen each of the screws without removing the nut, make the adjustments, and tighten back down. If necessary, you can use tape again to hold the frames in place while you tighten the screws. 

c. Ensure the frames are flush with your door and are sturdy.

Step 9: With a silicone sealant of your choice, we recommend sealing any gaps on the corners of the inside of the frames, as well as anywhere the two frames meet.


What's the difference between the single flap and the double flap?

The double flap option provides increased insulation against the cold. Both options have magnets on the flap to keep the door sealed in wind.

I want to get the large pet door for my dog, but I am concerned about a person fitting through it.

All Dragon Pet Doors come with a locking cover. This cover can be used to keep you doggy in. It also can be used to keep intruders from entering your home. It slides into the interior frame.

How do I know what size is best for my dog?

When installing the pet door you want it to clear the top of your dog's back by 1-2 inches, minimum. To give your pet the most comfortable pet door possible, make sure the step-over is less than 1/3 of your dog's height. Lastly you want the width of the door to be big enough to allow your pet to go through without touching the sides. Here's a guide on how to measure your pet with tips on how to determine the correct size.

Are replacement flaps available?

Yes, you can buy Dragon replacement flaps.

Where can I install the Dragon Pet Door?

The Dragon Pet Door has multiple Installation options. You can install it in Regular Doors, as a Wall mount, Aluminum Sliding Doors, Vinyl Sliding Doors, Sash Windows, Vinyl Windows, and Horizontal Windows.

Can my small and large dog share this pet door?

Yes, but make sure to follow standard Measuring Guidelines. Make sure the size of the door is based off your tallest pet, but installed low enough for your smallest pet.

Is the Dragon flap for door mounting the same as the wall mount?

Yes! The flap and frames are identical, the only difference would be the hardware that is included for installation.