How to Divide a Double Parlor Into a Bedroom & a Living Room

Measure the dimensions of the room using a tape measure, and decide what the finished size of the rooms will be. Determine whether the ceiling joists will be parallel to the new wall, or perpendicular to it. If they will be parallel, you must use studs to block the space between the joists to nail the top plate into the joists. If they will be perpendicular, you can nail into the joists where the wall is.

Place two 2-by-4-inch boards on the sawhorses. Determine the length of the wall you will erect, and cut the boards to that length using a circular saw. These boards will form the top and bottom studs of the wall frame.

Measure 1 1/2 inches in from the end of the top and bottom studs. Mark a line with a pencil across the boards at those spots. Mark an X to the left of the lines. Starting from the line you just drew, measure the entire length of the top and bottom studs with a tape measure and mark the stud every 24 inches. Place a combination square at each one of the 24-inch marks and draw a straight line. Place an X on the left side of each line. This is where you will install the wall studs.

Determine the number of 2-by-4-inch studs you will need to complete the wall, and place that number of studs on the sawhorses. Starting from one end, measure the height of the desired wall, minus 3 inches, and mark your studs at that length. Cut the studs at the marks using a circular saw. Assemble the wall frame by nailing the wall studs between the top and bottom studs using a hammer and 16d nails. The studs should be attached to the top and bottom boards at the lines you drew in Step 3, on the side where you put the X.

Stand the wall frame upright, and place in the desired location in the room. Use a framing square to ensure the new wall is square with the existing walls. Secure the top plate of the frame to the joists in the ceiling using a hammer and 16d nails.

Decide where you will put a door, and cut away one of the wall studs in the area where the door will go. Nail 2-by-4-inch studs into place on the sides of the door opening. Determine the length of the header for the door by measuring the space between the two studs you just attached for the door frame. Use a tape measure to measure the door header and cut it to size using a circular saw. Nail the header in place on top of the two support studs.

Measure the distance between the header of the door frame and the top plate using a tape measure. Cut a 2-by-4-inch stud to that length using a circular saw, and install it between the top plate and the door header where a wall stud would otherwise be. Nail it into place using a hammer and 16d nails.

Secure the bottom plate to the floor using a hammer and nails. Install drywall on both sides of the wall frame. Use a drill, screwdriver bit and drywall screws to secure the drywall to the studs. Drive the screws far enough into the drywall so you can hide the screw head with drywall compound.

Spread drywall compound over each of the screw heads using a spackling knife. Spread drywall compound over the gaps and joints in the drywall. Place drywall tape over the compound on the cracks, and cover the tape with another coat of drywall compound. Allow the drywall compound to dry for 24 hours and sand it smooth. Repair any cracks with fresh compound. Allow it to dry and sand it again.

Place the pre-hung door into the door frame and nail it into place using a hammer and nails. Caulk around the edges of the trim on the door to seal any cracks. Install trim molding as desired on the new wall and finish it by painting it the color of your choice.