How to Make an Opening Between Two Rooms Under a Structural Beam

Build a support system to hold the weight of the structure above before opening the wall. Have two helpers hold a 2-by-12-inch board against the ceiling parallel to the wall in question, and place a second 2-by-12 directly below it. Use 2-by-4-inch studs to wedge the board in place. Start at one end of the board and place one end of a 2-by-4 against the 2-by-12, then use your hammer to move the bottom end so the stud is as close to vertical as possible.

Repeat the process with a second 2-by-4 so the two form an inverted "V". Repeat the process at the other end of the 2-by-12 so it is firmly wedged in place. Use your screw gun to drive drywall screws through the tops of the studs and into the 2-by-12 to hold it steady. Move to the opposite side of the load-bearing wall and build another support structure there.

Remove the wall covering to gain access to the structural framework below. Use a crowbar and hammer to break away drywall and use a reciprocating saw to cut away any wood paneling or lathe. Use your reciprocating saw to cut off each vertical stud where it meets the joist or beam at the top of the wall. Cut off the studs at the bottom and remove them.

Measure the opening from floor to ceiling at both ends. Use your circular saw to cut two 2-by-4's to fit and install one at each side of the opening. Use your hammer and nails to fasten these king studs to the floor at the bottom and the ceiling joist or beam at the top.

Cut two 2-by-12-inch boards to the length of the wall opening with your circular saw. Cut a strip of 1/2-inch plywood the same length and width as the 2-by-12's. Apply a bead of construction adhesive to both sides of the plywood and use your hammer and nails to fasten the 2-by-12's together with the plywood sheet in the center. This will serve as your support beam.

Measure the distance between the floor and the top of the opening with your tape measure and subtract the width of the support beam. Cut six 2-by-4's to this size. Stand one 2-by-4 at each end of the wall opening and slide the support beam over them and into position across the top of the opening with the help of your assistants. Use your sledgehammer to drive the beam into position if it proves too difficult by hand.

Use your hammer to position the remaining support studs under each end of the beam so they fit tightly together. Drive nails through each stud and into the next as you go. Drive nails through the full length stud at the end of the opening and into the shorter studs and the beam itself. All of the elements of the beam and support system should be fastened together tightly and flush with one another.

Install one more 2-by-4 at each end of the opening, outside of the king stud. Use your hammer and nails to fasten it in place. Install plywood and molding around your new opening.