FAQ Knowledge Articles

The Ultimate Outswing French Door utilizes a thermally broken sill.  This is accomplished through the use of a polypropylene key that separates the exterior aluminum from the interior aluminum.  The break will reduce the transfer of hot and cold temperatures from one side to the other.

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The Marvin Ultimate Inswing French Door is unable to use a thermally broken sill due to the location of the door panel.  There is no room to place the key to stop the transfer of temperature.

Commercial Doors have a thermally broken sill as a standard 1/4" or 1/2" option.