Then cut and install 1x3 fascia over the 1x4 fascia. Use treated lumber for the corner boards since they're in ground contact. Cut the corner boards to size and nail them into place with 8d nails.
Set the beams across the floating deck blocks and square them to each other, using the same 1x4 stretchers to hold them parallel and square ... Nail 1/4-in. spacers ripped from treated wood to the rim ...