May 13, 2020 — 2 and better (no loose or missing knotholes), then a 4x6 spanning 18' will support about 105 lbs. How much weight will a 6x6 post hold? As this .... The design loads for 4x4 and 4x6 lumber for the commonly used ... AXIAL COMPRESSION LOAD CAPACITY FOR 4x4 AND 4x6 COLUMNS. Column ... You can receive a publications order form ... bracing or lateral support except at the ends .... The amount of weight that a 4×4 can support horizontally will depend on the type of wo