03-12-2012, 03:41 PM
Only reason you should need screws longer than 3-3.5" is if the door was not framed correctly. Use billb's suggestion of using a piece of stiff wire to probe through the existing screw holes in the jamb and see how far it is until something solid. Builder could have cut corners and not run a jack stud the full length or just used scraps and hid it with the trim. You might have to take off the trim and add blocking or shims in the area of the hinge if the gap is too large, otherwise tightening long screws through an empty gap could distort the door frame.