How to Measure & Cut a Doorway in a Wall for a Prehung Door
- 1). Locate any existing wiring, plumbing and studs on the wall you intend to convert to a doorway, using blueprints and a stud finder. This will help you avoid complications once you begin to cut through the wall. Locating studs helps you determine the most structurally sound location for your doorway.
- 2). Measure the door and frame with your measuring tape for height, width and depth. Using a plumb line for accuracy, trace the measurements of the door frame on the wall. Trace an additional 6 inches for the amount of drywall to be removed from the existing wall, which will create the rough opening.
- 3). Using a utility knife for drywall or a reciprocating saw for plaster, remove the drywall or plaster in the area marked for the rough opening. Cut neatly and don't cut too deeply at once. You may find that cutting the opening in a grid pattern gives you more control over the wall removal.
- 4). Cut the opening for the door frame by first measuring the stud area to determine which stud work needs to be removed. Using a reciprocating saw, remove any existing studs that are in the way of your door. Load-bearing walls must first be supported at the ceiling level, before stud removal.
- 5). Build in new studs to frame the doorway. Measure your lumber and cut it to fit the exact size of your door frame. Make sure the studs fit tightly and make sure they line up flush with the floor and ceiling horizontal studs. Nail the studs in with a nail gun into the horizontal floor and ceiling studs.