How to Build a Bedroom Wall With a Doorway

Building the Wall Frame

• 1

  Use a stud finder to locate the studs in the intersecting walls where you plan to attach the new wall.

• 2

  Mark the location of the new wall onto the intersecting wall, then measure the distance between the mark and the corner of the room. Repeat for the other end of where the new wall goes. Measure corner to corner in an "X" pattern to ensure the room is square. When square, the two measurements match.

• 3

  Snap a chalk line between the two marks to run across the floor as a guide for installing the wall.

• 4

  Cut away 4 1/2 inches of the molding along the base of the intersecting wall where the new wall abuts using a reciprocating saw. Allow for the cut lumber measurements and a 1/2 inch of drywall on each side of the wall. Repeat for the other end of the wall.

• 5

  Measure the width of the prehung door, and make a mark for each side of the door onto the chalk line where you plan on installing the door.

• 6

  Measure the distance between the side walls and the marks you made on the floor for the doorway, and subtract 1 1/2 inches from the measurements. Cut a 2-by-4 board to fit along the chalk line between the wall and the mark for the door. These boards are the bottom plates for the wall frame. Subtract 1 1/2 inches from each side to account for the king studs in the doorway frame.

• 7

  Cut a 2-by-4 board top plate, the length of the entire wall.

• 8

  Lay the top plate onto the floor along the chalk line, and place one of the bottom plates atop it. Measure the distance between them and the ceiling for the stud height.

• 9

  Divide the length of the sill plate by 16 to calculate the number of studs needed for the wall, 16 inches on center. Cut the studs using the circular saw.

• 10

  Stand one of the bottom plates on its 1 1/2-inch edge, and nail one of the studs flush to its end by driving two nails through the bottom of the plate and into the end of the stud, using 2 1/2 inch nails. Repeat this every 16 inches on center. Construct the wall flat on the ground; lift into place when complete. Repeat the process for the other side of the doorway.

• 11

  Place the top plate along the chalk line, and mark the measurements for the door frame onto the top plate. Line up the assembled framing with the marks on the top plate and repeat the process used with the bottom plate to attach the top plate to the studs.

• 12

  Lift the frame into position, lining up the bottom plates with the chalk line. Have someone help you lift the wall. Nail the framing to the walls, ceiling and floor, driving the nails through the framing in a zigzag pattern approximately 6 to 8 inches apart after checking for plumb and level.

• 13

  Measure the height of the prehung door framing, and cut two 2-by-4 boards that match that height as the jack studs. Nail one jack stud to each king stud aside the door opening on either side, using 2 1/2-inch nails in a zigzag pattern, approximately 6 to 8 inches apart along the length of the stud.

• 14

  Measure the width of the doorway, and cut a 2-by-4 board to fit that width as the header. Place the header horizontally atop the jack studs, and drive two nails through the king stud into the header ends on both sides.

• 15

  Measure the distance between the top of the header and the top plate, and cut a cripple stud to fit. Nail these between and to the header and top plate, positioning them 16 inches on center from the king studs. Toenail through the cripple studs into the top plate at a 45-degree angle.

Finishing the Wall

• 16

  Cut sheets of half-inch drywall to fit on the wall. Cut the drywall by marking the cut line onto the board, then holding a straightedge against the line. Run a utility knife over the line to score the drywall, then snap it at the score line.

• 17

  Place the first sheet on the frame, with one edge against the side wall, and screw it to the studs and top and bottom plates with drywall screws. Use one screw every 16 inches. Install the drywall on the rest of the framing, using the same method.

• 18

  Spread joint compound onto the joints between the different drywall sheets with a 6-inch putty knife. Place drywall tape over the joints, then push it into the joint compound by running over it with the putty knife. Allow it to dry overnight. Sand the joints with fine-grit sandpaper to smooth them out, then wipe the dust off with a clean rag. Repeat this step two more times.

• 19

  Place the prehung door into the doorway opening. Check the door for level, and center it inside the framing of the wall. Place shims between the prehung door and the wall's frame to center it, if needed. Trim the shims with a utility knife. Nail the door to the wall frame with 10d finishing nails. Drive the nails through the shims and door jambs into the wall framing. Finish by adding molding and paint to the wall.