How to Install a Beam Into an Existing Wall Using Joist Hangers

Drag the stud finder across your wall. Make a pencil mark where the indicator light illuminates, then again where it goes out. Mark the location of two studs that are side by side. Repeat the process, finding two studs on the opposite wall, directly across from the first set.

Hold a 17 1/2 inch board up to one wall. Slide it up next to the ceiling. Be sure the outer edge of the board lines up with your outer stud marks. Use the Phillips bit on your drill to drive three screws through the board 3/4 inch from each end to attach the board firmly to the studs in your wall. Attach the second 17 1/2 inch board on the opposite wall.

Use your tape measure to find the center of both boards. Measure between the two marks. Transfer this measurement to your 20-foot board. Cut the board to the proper length. Hold one end of the board against the center of one of the wall-mounted boards while your assistant lines up the opposite end of the board.

Drive three of your 8d nails at an angle through the end of the beam and into the wall-mounted board. Drive three angled nails through the other side to secure your end of the board. Switch places with your assistant. Hold a large speed square against your beam and the wall-mounted board. Adjust the beam to be sure it is at a perfect 90 degrees to the wall. Toe nail the beam in place.

Slide a joist hanger up under one end of the beam so that it cradles the board. Hit the frame of the hanger to drive the retaining spikes into the wall-mounted board. Drive a Tico nail through every retaining hole in the joist hanger to secure the hanger against the beam and the wall-mounted board. Install the remaining joist hanger on the opposite end of the beam to complete the installation.