A prehung interior door saves the do-it-yourselfer a considerable amount of work as the hinges have already been established in a framework that is ready to install on your rough opening. Installation is a matter of cutting the legs to adjust the door jamb for particular soil, and then leveling the door opening. When you buy your pre-hung door, make sure the hinges are correctly oriented in the room in which you are installing the door so that the door is in the right direction.
Instructions to install prehung interior door: measure the opening in the wall where you want to install the door. A door should be hung on the jamb to open in a room in a specific direction and this will determine the side on which the hinges are fixed. Check square opening to determine in advance how much will be needed fit.
Cut the jamb legs to adjust the final height of the door. An interior door should have about ½ inch of air space at the bottom of the door. Doors are usually shipped pre-assembled with legs that are longer than necessary so you can adjust the height for different flooring materials such as tiles, wood and carpet piles different. If the floor of the opening in the wall is not level, it can also be cut to different lengths the legs to level the door in opening.
Place the door assembly in the opening in the wall; make sure the wood jamb is lined with drywall on both sides of the opening.
On the hinge side of the door, place shims between the jamb and the door frame until the level indicates the sinker. 10p Use finishing nails to secure the door jamb to jamb rough. Drive nails through the wedges, leaving about ½ inch of exposed cases in nail adjustments are needed. When the door installation is complete, set nails.
Follow the same procedure as above, using shims to create a further space between the edge of the door and the jamb. Nail the door in place by wedges.
Finally, to install prehung interior door, check the space on all sides of the door to make sure it is even. Test the door swing to make sure that does not bind at any point of its movement. When satisfied with the fit and movement of the door, trim the nails and trim excess material wedges.