Patio Pet Door Panel Installation in Monorail Track Sliding Glass Doors

Over the years we have become accustomed to the traditional ‘U’ shaped tracks in most sliding glass doors models.  The original Patio Pet Door Panels were designed to work with this style of track. There is an emerging trend in sliding glass doors to eliminate the bottom ‘U’ shaped track, 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. 


Monorail                                                                  ‘U’ Shape

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 Patio Pet Door Panel to be secured to the track. This can be accomplished in one of two ways.

  1. Toe-nail the bottom of the panel into the monorail track using screws – this is a semi-permanent installation
  2. For the Endura Flap Thermo Panel 3e an adapter may be an option.  If your monorail is less than 3/4″ thick, you can install the Thermo Panel 3e with some modification to the bottom of the panel. You will need to contact customer service to order an adapter (pictured below) that is not sold on our website. This will be a custom installation requiring the use of a power drill and possibly a jigsaw. Once these modifications have been made, the panel will not be returnable.

Adapter -> 

The second 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. Here are a couple of pictures of an Endura Flap Thermo Panel installed in a monorail sliding glass door.


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.  

Each manufacturer and model of sliding glass doors can be 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.  They’re available Monday- Friday, 7am – 4:30pm Pacific time for calls or on-line chats. Pictures can be useful in determining the best solution for your specific situation. You can email them to  

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