My shed foundation consisted of 9 concrete filled post holes, with a 200 mm post bracket embedded in each. I worked on the corners first, and placed the portholes and brackets at 2800 centers. This provided a 100 mm overhang on each end. The intermediate posts we place between the centre of the 2800 spaced posts, or at 1400 mm apart. I then placed 3 - 100 x 100 posts horizontally to act as the beams, and then place 150 x 45 joints perpendicular to the beams. All joints tied in with coach screws. Between each joist, l placed spacers for stability staged at approximately 600 centers.