Place shims around the edges and top of.
How to install a sliding door.
Apply wood glue on all top surfaces of the pieces of both your inner and outer frames.
Flip the door so that the newly attached plywood side faces down.
Use shims under screw holes to help keep your threshold in good shape.
Begin positioning the door into the opening from your exterior area.
Place the plywood on top of the frame apply wood glue and secure it with screws once it s aligned.