Ok, so this is the year I am going to finally build my woodshed. I am going to go with a simple version of the attached plan. My question is on the header size...the plan is for a width of 8 feet, and I would like to make it about 10 or 12 feet long. The plan calls for a 2X10 header...if I increase from 8 feet, to 10 or 12, would a 2X10 header still be sufficient? (Side posts are going to be 4X4's and the joists will be 2X4 16" on center)