Let's see what I can do...

Let's call that a 32 x 42 building; that = 1344 sq ft.

Divide that into three parts = 448 sq ft per section

Let's call that 450 sq ft.

If we call the LL to be 40 PSF, let's call the DL out at 15 PSF.

That's a floor load total of 55 PSF

450 x 55 = 24750 on each floor segment.

Half of that will rest on the center beam and a quarter on each side wall.

24750 / 2 = 12375 on the center beam for each segment.

Using

**Don_P's simple beam calculator** and the following data for SYP...

Modulus of Elasticity (E) 1600000 psi

Bending Strength (Fb) 1120

Shear Strength (Fv) 175 psi

(the calc is fixed to use a value of L/360 on floors)

But let's see what happens when we use...

a beam length of 13'4"

and 12500 lbs as the beam load

Hmmm. The calculator tells me that 4 layers of 2x12 (actual beam width of 6" and depth of 11.25" will FAIL the Fiberstress in bending test and the deflection test. Horizontal shear passes.

Using three columns across the length reduces the span for each to approximately 120" (10 ft)

And changes the segments to 4, giving...

1344 sq ft / 4 = 336 sq ft per segment

340 x 55 = 18700 PSF

18700 / 2 = 9350 lbs per beam segment

Call that 9500 lbs

Hmmm.

That still FAILS the fiberstress in bending test.

Perhaps you need some engineered wood, or steel.

Or yet another column?

Or I did something wrong?

Hopefully Don_P will be along sometime soon and see if I have messed up or not.