How to Install a Large Pet Door

Installing a large pet door differs only in scale from installing a smaller pet door.

Check the Pet Door Kit

Check the pet door kit that you have bought to ensure that all the parts are included, as well as fully comprehensive fitting instructions. Read the manufacturer’s instructions and ensure that you have all the necessary tools at hand.

Ensure That You Have The Right Size Door

It is always wise to check the pet door size before starting to install it. The door installation kit should contain a template to help position the pet door. See if your pet can walk through the template with ease. If the template is not strong enough, use it to mark out the size of the pet door on a large piece of cardboard. Cut it out and check that your pet can walk through it.

Attach the Template to the Door Where the Pet Door is to be Fitted.

The template should be securely fixed with adhesive tape so that it does not move. Carefully mark the perimeter of the pet door aperture by penciling round the inner edge of the template. The top of the template should be fitted so that the upper edge of the position of the pet door aperture is at the height you measured against your pet.

Drill Holes for Fitting Screws

If the door you have bought is secured by screws the template will indicate where those screws should go. Mark the position of these holes carefully. Remove the template and drill the holes.

Cut Out the Opening for the Pet Door

Drill holes large enough to accept a jigsaw blade as tight as you can into the corners of the marked opening. Do not drill outside the drawn frame. Use the jig saw to cut out the opening.  

Insert the Outer Frame into the Aperture.

The outer frame of the pet door is the one that does not have the flap. It should be inserted from the outside face of the door. If the frame extends beyond the inside face of the door, remove it.

Resize the Frame

You will notice that the inner edge of the frame is scored. These score marks indicate the location of snap points along which parts of the frame can be removed to make it fit flush to the door. Use pliers to snap off a layer at a time until, putting the frame back in the door, it no longer extends beyond the inside face of the door. You can put a small draft proofing strip around the aperture before fitting the frame.

Fit the Inner Frame

Once the outer frame is correctly resized you can fit the inner frame. This will be secured to the outer frame using screws for which you have already drilled holes in the door. Tighten the screws and your pet door is fitted.

Fit any security devices that came with the pet door and then your installation is complete. Let your pet give it the final test.