How to Build an Extra Load Bearing Wall Truss

Measure the length of the support beam for the wall in which you intend to install the extra load bearing truss from the inside of the two connecting studs at either end. This is where your additional support truss should be installed once you brace the wall and remove any studs in between that may get in the way of the truss.

Cut two 4-by-6 pieces of wood that are each the length of your previous measurement using a table saw or a circular saw. These serve as the cross beams in your truss.

Divide the number of feet in length that your truss is by three and then add one to calculate the number of cross-supports needed for your truss. Or, if your truss is not easily divisible by three, take the number of inches and divide by 36. The resulting number is the number of cross supports. For instance, if you have a beam 144 inches long, you need to cut five of these supports. Two should be used on either end, with three between the two larger beams.

Cut the number of 2-by-4s to be used as cross supports using a circular saw or table saw.

Glue two of the cross support beams on the inside of the two large beams of the truss, so that the boards are flush with the end of each of the main support beams, but on the inside of each. Drive 3-inch galvanized steel nails diagonally through the cross beam into the main support beam.

Mark the main support beams in three places using the measurements you determined earlier. In the case of a 3-foot cross support, place the supports 36 inches apart from center to center.

Place the boards between the main support beams at the marker you have created. Glue and nail each support in place. You should now have a truss made up of four equal-sized squares or however many squares you measured for.

Cut an equal number of additional cross supports the same length as the ones you just attached to the main beams. These serve as diagonal cross supports. Using a compound miter saw, cut a 45-degree angle from the end corner of each piece. Each 2-by-4 should have two 45-degree angle cuts on opposite sides of the board. When you affix each cross support, the angle should line the cut edge up with the inside of the vertical cross support beam.

Glue the cut edge of the diagonal support beams before putting them against the vertical cross supports. Predrill holes on the outside of the vertical support and then use 3-inch wood screws to connect the diagonal support to the vertical beam.

Reinforce each corner of each triangle formed with a metal or plywood connecting joint.