I used cedar 1x4’s for the top of the shelf. I cut 4 pieces to 35 inches in length. I used 4 cedar 1x2’s for the bottom supports. They’re roughly 14 3/4 inches long. I spaced the 1x4’s about 1/4 inch apart. I glue and screwed them together from the bottom through the 1x2’s.
I sanded and put 2 coats of spar urethane on all of the boards prior to putting everything together.