I'm looking to add a 24'x24' mezzanine into an existing pole barn. Pole spacing 8' oc. I need to figure out LVL and Joist sizing. My plan is for (2) of the LVLs to span 20' one side bearing on a stud pack and the other bearing on a 2x6 bearing wall. (1) LVL will be 24' bearing on stud packs...