I need to build a simple fire wood storage shed with roof, size of shed
8 x 10 ft.. I will use some concrete blocks for footing, and
2x8 for framing. My question is what size of posts I should consider for such shed,
I have built 3 sheds using two 2X4 at each corner ( two were 8' X 12', one was 8' X 16' and 2 stories). I used 2 X 4 on 16" centers and 1/2 " plywood walls. None fell down or blew away. All were set on flat concrete or cement blocks. The compressive strength of southern pine is about 13,000 psi so using a design value of 5000 psi appears safe. As noted you do need some structure/diagonals for stability for loads from various directions.