The original blueprints for the home will tell you which walls are load bearing and which ones are not. If a wall is marked as “S” in the blueprint, this means “structural,” thus showing it’s a load-bearing wall.

What size beam do I need for a load-bearing wall?

The formula for the section modulus is beam width times beam depth squared divided by 6. A two 2-by-6 standard beam has actual dimensions of 1.5-by-5.5 inches which would give a section modulus of 1.5 x 5.5 x 5.5 / 6 = 7.6 which is not enough for this example. A 2-by-8 beam would be sufficient.

What kind of beam do I need for load-bearing wall?

horizontal structural beam





Beam Only – This should be a horizontal structural beam that is of adequate size. Apart from the 2 ends, the beam will have no upright bearing points.

Can you put a beam on a load-bearing wall?

If it’s a load-bearing wall, the inspector may help size the beam or recommend that you have a structural engineer or architect size it. The inspector will check the size, issue a permit and check your work when you’re finished framing (before you start any drywall or finish work).