Leave 10 boards 96 inches long (or cut them to your specified length) Cut 2 boards 89 1/4 (this measurement will change if you shortened your table) You need 4 pieces 30 inches long 4 pieces 36 inches long 1 of your longest pieces of extra (as close to 36 inches)
Lay down one of your 36 inch boards and drill into it the 30 inch boards coming up from the ends. You will then have a U Then you need to drill your top cross beam in. Paint w/ outdoor paint.
Next, you will attach the last 36 inch board to the middle of the under side of the table.