How to Replace a Sliding Glass Patio Door With French Doors

Updated April 17, 2017

Sliding glass doors are a common feature in modern homes, but some are less energy efficient than others. Newer models are more efficient, but homeowners may not find them attractive. French doors are a desirable replacement -- not only do they add charm to your home, but they are also great for letting in light without losing heat or cool air. Most designs have a decorative frame inserted between two panes of glass, which create the appearance of multiple small windows. Some prefer French doors without decorative inserts; these are also available.

Remove the moulding from around the inside of the existing sliding glass door using a hammer and pry bar. Measure the rough opening of the wall in which the sliding glass door is installed using a tape measure. Purchase the French door set to match the size of the opening in your wall. Remove the screen from the sliding glass door unit by lifting it up and pulling the bottom out first.

Remove the lower track on the outside of the door using a flathead screwdriver to pry it up and out of the track. Remove the screws from the stationary door using a Phillips screwdriver. Slide the stationary door to the centre of the track. Lift the door and pull the bottom away from the track. Lower the top out of the upper track and away.

Remove the sliding door in the same manner that you removed the stationary door. Remove the door frame from the opening using the Phillips screwdriver to loosen the retaining screws. Use the pry bar and hammer to remove the framework from the opening. Run a wide bead of caulk on the bottom of the opening using the caulk gun. This seals the bottom and prevents air from escaping.

Set the pre-hung French door into the opening; centre the unit and check for level. Insert shims from side-to-side to keep the unit centred. Screw one screw on each side of the frame to hold it in place. Spray small amounts of foam insulation in the opening around the door frame. Do not over-spray the foam, as it expands rapidly and can buckle the frame. Install the remaining screws and secure the door frame.

Remove all clips securing the doors and test them for proper opening and closing. Install the door hardware using a screwdriver. Place the finishing trim around the door frame, both inside and out, using the hammer and finishing nails. Run a bead of caulk around the entire door frame using the caulking gun. Paint the doors and finishing trim.


While one person can install the French doors, it is always best if you have a helper.


Continuously check the doors for level as you install the unit or it may be difficult to open and close them.

Things You'll Need

  • Tape measure
  • Hammer
  • Pry bar
  • Shims
  • Screws
  • Screwdriver set
  • Level
  • Caulk
  • Caulk gun
  • Foam insulation
  • Finishing nails
  • Paint
  • Paintbrush
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About the Author

John Rose has been writing professionally since 1981. Now contributing to various online publications, he specializes in auto repair, home maintenance and similar topics. Rose studied English at Frostburg State University.