How To Install a Flat Jamb Interior Door - The Home Depot

The installing of flat jamb interior door is a project that could be easily accomplished by the average do-it-yourselfer. On a scale of one to five, with five being very difficult, this project is a two. Installing of pre-hung flat jamb door is a little different than installing a pre-hung split jamb door. Unlike split jamb doors, flat jamb doors, don’t generally come from the factory with the casing already attached. The casing comes with the door, but must be hung in a separate step. Always ensure that you have the following tools and supplies when installing a pre-hung flat jamb door; a hammer or a pneumatic nailer, finishing nails, a carpenter’s level, hand saw or utility knife, shims, a door handle and of course, safety glasses.
Before you get started with the installation, remove all packing materials, blocks, and nails from the door assembly. Now, place the closed door in the rough opening and center it. Tap shims into place between the doorjamb and the rough framing to make the jamb plum. To hold the door in place, nail through both the jamb and shims into the wall stud near the top hinge using a finished nail. Do the same for the other hinges. Check the doors alignment with the level again before continuing around the door jamb installing shims and nails in the same manner. The space between the jamb and door should be the same for the entire length of the unit. Most contractors; like to leave about a quarter of an inch space between the door and jamb. This space is commonly referred to as the reveal.
Next, trim any shims that protrude from between the jambs and framing. Put the door casings into position and nail them in place. As a finishing touch, most installers will apply cock to cover any gaps in the casings miter joint. As a final step, you would install the door knob and related hardware according to the manufacturer’s directions.


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