Things You'll Need
3-inch wood screws
1-inch drywall screws
If you've renovated an older home or divided one into apartments, you may find yourself with a staircase that is no longer used. This can create an awkward flow in a house or cause separate apartments to be connected. This is easily remedied, however, by simply closing off the top of the stairs. Effectively, this involves building a wall to cover up the top of the stairwell, separating the top and bottom floors.
Measure the distance between the two walls at the top of the stairs, using the tape measure.
Cut two boards, the length of the opening width, with the chop saw.
Place one board in the opening, between the two walls, at the edge of the top stair. Screw the the board to the floor using the wood screws and electric screwdriver. The screws should extend into the stud framing the top of the stairs. Use one screw for every 4 inches of board, spacing them evenly.
Place the other board on the ceiling, parallel to the one on the floor. Attach it to the ceiling with the wood screws, just as you attached the board to the floor.
Measure the distance between the ceiling and floorboards that you have installed.
Cut a series of boards, the same height as the distance between the installed boards. You need one board for each 6 inches of space between the walls.
Place a board on each wall, between the floor and ceiling boards, and attach it with the wood screws, just as you did with the other boards. Place one screw every 4 inches, with the screw extending into the wall stud.
Place the remaining boards, one at a time, parallel to the upright boards, spaced evenly. Attach the boards to the bottom and top boards using the wood screws. Insert the screws at a 45-degree angle, into the upright boards, extending into the top and bottom boards respectively. Use four screws for each board, two at the top and two at the bottom.
Cut the drywall to fit the dimensions of the opening, with a drywall knife. If the opening is greater than 4 1/2 feet by 16 feet -- the largest drywall dimensions -- you'll need to use more than one sheet. You need enough drywall for both sides of the frame.
Place the drywall on one side of the frame and attach it to the frame with the drywall screws. Use one screw for every 4 inches of frame. Repeat the process for the other side of the frame.
For a more complete finish, consider removing the staircase altogether after closing off the top.