Depending upon the building, we traditionally use 3 ply laminated columns from Timber Technologies for the larger buildings and 5 x 6 solid full treated poles for smaller buildings.  Timber Technologies manufactures glue-laminated columns the highest standards, to provide a straighter, stronger, and more predictable column.  Timber Technology uses MSR 1650fb SPF Uppers and #1 SYP .60 CCA for ground contact lumber.