How to Close Up a Doorway

Remove the door from the opening, if one is present, by backing out the screws holding the door’s hinges to the door jamb. Insert a metal putty knife in the space between the trim around the doorway and the wall.

Pull the trim off the wall by sliding a pry bar between the putty knife and trim. Pull back on the pry bar to remove the trim’s nails from the walls, working from one end of the trim to the other with the putty knife and pry bar.

Cut through the nails you can see between the door jambs and the wall, which were previously covered up by the trim, using a close-quarters hacksaw. Remove the side pieces of the door jamb and cut through the nails above the header board.

Slide the putty knife under the edge of the transition strip in the doorway, if one is present. Insert the pry bar between the putty knife’s blade and the edge of the transition strip. Push down on the pry bar to pull up the transition strip.

Cut a 2-by-4 board the same length as the width of the door opening. Lay the board across the floor in the doorway and drive nails at an angle through the ends of the board and into the wall studs.

Measure the distance between the board you installed in the bottom of the doorway and the top of the doorway. Cut two 2-by-4s the same length and position them on either end of the opening. Drive nails through the new 2-by-4's and into the adjacent wall studs, holding them in place.

Measure the gap between the vertical boards you nailed in place and cut another 2-by-4 to fit in the gap. Hold the new board at the top of the doorway opening and drive nails through it and into the wall studs above.

Cut another 2-by-4 to the same length as the gap between the bottom board and the top board you installed in the doorway opening. Insert the board vertically in the opening, in the exact middle of the opening. Drive nails at an angle through the top and bottom of the board, attaching it to the horizontal boards you installed.

Measure and cut drywall sheets to fit in the old doorway gap, on both sides of the wall. Drive screws through the edges of the drywall sheets and into the boards you installed in the wall. Lay drywall tape over the seams between drywall sheets and apply an even and flat coat of drywall compound. Sand the edges of the compound, after it has dried.