Step 11: Trim the bottom of the posts
The metal post bases will prevent the 1×4 trim boards from fitting snugly against the posts. Before cutting the trim boards (G), run the full-length cedar 1x4s vertically through a table saw a couple times until about 3/16 in. of material has been removed.

Fasten the trim boards to the posts with an 18-gauge trim gun fitted with 2-in. galvanized brad nails (Photo 13). Strengthen the joint by applying construction adhesive before nailing them together. Secure them with brad nails at the top of the boards and through the miters. Install them up away from the ground to keep them dry.

Step 12: Assemble the tabletop and shelf frames
Cut the table frame ends and center braces to size (H and J). Use a square to mark a line on both posts up 41 in. from the slab. That will be the top of the frame. Install the ends 1 in. away from the outside edge of the inside post, and secure them with 3-in. exterior wood screws, two in each post. Measure and cut the table frame sides to size (K). Install the board with screws angled into the post. This keeps them from being visible after the top is installed.

Measure the distance between the posts and cut the cedar 2×4 that will serve as the skirt nailer (L). Center it on the outside post, which leaves 1 in. on each side. This will make the skirt boards flush with the outside edge of the posts.

Install the center braces (J) 20 in. in from each post. Secure them by angling two screws into the side boards (so they’re not visible) and one down into the skirt nailer (Photo 14).

Cut the shelf frame ends and centers to size (M and N). Use a square to mark a line on both posts up 15 in. from the slab. That will be the top of the shelf frame. Install the end pieces so they overlap onto each post 1 in. Cut the shelf side boards (P). Secure them to the end boards with screws. No need to angle these screws because the outside screws will be covered with the skirt boards, and the inside ones are too low to notice. Install the shelf center boards, 20 in. in from both posts.

Step 13: Install the tabletop, shelf and skirt boards
Cut the deck boards for the table top (Q) to fit between the posts at each end. Secure them with two 2-in. exterior-grade trim-head screws through each deck board. Keep the screws about 1 in. from the edges of the deck boards. Start with the table-top board closest to the inside, and line it up with the edge of the inside posts (Photo 15). There’s no need for a gap between the boards.

Measure and cut the shelf boards (R) to length. Rip two of them down to 4 in. Install the cut end flush with the outside edges of the shelf frame so they’re hidden by the skirt board.

Cut the skirt boards (S) to length. Center the first one between the posts and install it with two trim-head screws to the skirt nailer and shelf frame. Work your way in each direction, and trim down the last skirt boards to fit flush with the posts.

Remove all the temporary braces and touch up all the cut ends of the boards with stain. All that’s left is to slide your grill into place and invite the neighbors over for a party under your barbecue gazebo.

Project step-by-step (15)