Sliding doors run along two tracks: one at the top of the door and one at the bottom. Small wheels or bearings sit at the top and the bottom of the door that slide along the track, making the door move easily. Over time, your old doors may need replacing due to wear and tear. You may even have old sliding glass doors that have only a single pane of glass, making them less energy-efficient than new models.
Remove the trim from the old door by prying it off with a pry bar. Remove all stops and trim to make the old doorway as light as possible. Remove both the interior and exterior trim.
Remove the screws that hold the door frame into the rough opening. Remove all the old nails then tap the frame with a hammer to loosen it from the rough opening. Lift the frame out of the door.
Check the rough opening with a carpenter's level to see if the area is plumb. Pound in sawn pieces of plywood to make it even, if you find the rough opening to be uneven.
Run foil-backed tape along the sill to make it watertight if the sliding door is going into the exterior of the home.
Run three bands of waterproof silicon along the sill of the door. Place the bottom of the door frame in place and slowly lift the door frame up until it is secure.
Slide frame studs between the rough opening and the frame of the sliding door, and use the level to even out the door in the rough opening. Nail the studs into place once the frame is even.
Screw the door frame into the opening using the package instructions. Add the trim according to the instructions using 8d finishing nails.
Lift the door into the frame by placing the bottom of the door onto the track and lifting up into place. The wheels will pop into the track, locking it in. Remove any stickers from the door.
Replace framing boards that show any signs of rot or water damage.