Patio Pet Door Panel Installation in Monorail Track Sliding Glass Doors

patio pet door panels in silver and white - pet sliding door installation

Over the years, we have become accustomed to the traditional ‘U’ shaped tracks in most dog door for slider models. There is an emerging trend in sliding patio doors to eliminate the ‘U’ shaped track on the bottom rail (sometimes the upper one too) and replace it with a monorail-style track where the sliding door rides on top of the track instead of in a channel. The image on the left shows a monorail track, the one on the right shows the traditional 'U' shaped track. 

proper installation of patio door in monorail track requires an adaptor

This new design presents challenges for the Patio Pet Door Panels which use the ‘U’ shaped track walls to hold the bottom of the panel in place. The monorail style requires the panel to be secured to the track. This can be accomplished in one of two ways:

First Method: You can toe-nail the bottom of the panel into the monorail track using screws. This stabilizes the panel and becomes a semi-permanent installation. 

sliding door pet door adaptors - install dog door in sliding glass door


Second Method: For the Endura Flap Thermo Panel 3e, check out this Monorail Adapter, which provides a channel for the panel to sit in. It fits over tracks 3/4" wide x 3/4" high, and requires the use of a power drill. 

view of the sliding glass door bottom track for how to install a sliding door monorail panel

The adapter method will not put holes in the monorail, but may take a little more handy work to install. The finished installation looks nice, is securely installed in place, and can be removed. The same steps can also be used for large window sliders that have the monorail type track. 

Unfortunately, it will not work for other brands like the Ideal Fast Fit Slider Insert or the Pride Patio Pet Door Panel

When measuring the track height for the monorail design, you will need to measure from the top of the bottom monorail to the highest point in the upper track. You'll also need to measure the thickness of the monorail itself.


how to install sliding door insert with monorail track  

Tip: If you want additional light filtering and energy efficiency for your door panel, you can install window treatments like drapery, door blinds, door curtains, and other window coverings to block sunlight from coming inside.

While some door panels, such as the Endura Thermo Panel, have Low-e glass to block heat and UV light while giving an unobstructed view, not all door panels do. Another option would be to apply a room darkening or blackout film over the panel window in order to limit the amount of natural light coming inside.

Each manufacturer and model of sliding glass doors is different. If you need help understanding the differences, measuring, or purchasing the adapter, has a team of expert Customer Service Agents that can walk you through your options. See our post on how to install a dog door in a glass door for more information. 


  • Hi LHnTX,

    We may need a few more details to give you a proper recommendation for your situation. It’s possible that adding a ramp or some steps leading up to the pet door flap on both the interior and exterior side would be a great solution for your situation. Please reach out to us at 1-800-826-2871 or email us at so we can help you out!

    Happy holidays!

    Elizabeth (Staff)
  • Does someone have something that’ll fit in the patio door track other than a pet door so I can have a cable or a cord to PASS THROUGH but nothing else like bug & HOT/COLD air???

    James Van-Dusen
  • I have a vinyl sliding glass door with a monorail. I also have 5 chihuahuas. None of them would be able to step over that monorail adapter because it is so darned high.

  • Hi Gidfiddle,

    We may need a few more details to give you a proper recommendation for your situation. Please reach out to us at 1-800-826-2871 or email us at so we can help you out!

    Grace (Staff)
  • My sliding glass door is vinyl and has a monorail. The monorail adapters are said to be only for aluminum sliding glass doors. Is there any other way to install a dog door in my situation?


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