How to Build a Deck on a Sandy Beach

Dig eight equidistant holes 2 feet deep in the ground to make a 10-foot-by-10-foot square in the sand.

Place the first wood post in the ground. Place the level against one of the sides of this post and stand the wood post up until the horizontal level shows that the wood post is plumb (straight up). Fill the hole with concrete. Repeat this step with the other seven holes and allow the concrete to set overnight.

Place a joist hanger on the top of each of the posts. Drill into the post tops through the holes in each joist hanger, and attach each joist hanger to its respective post by tightening a wood screw into each drilled hole.

Place two planks together, face to face. Insert these planks into the joist hangers along the back side of the rectangle. Place the level at the top edge of the planks and adjust the alignment as needed to level the edge. Drill into the planks through the holes in each joist hanger, and attach the planks to each joist hanger, tightening a wood screw into each drilled hole. Repeat this step for the front side of the rectangle.

Measure the distance on the right side of the rectangle from the front right and rear right corners; this measurement should be slightly less than 10 feet. Trim two planks to this measurement using the miter saw. Place these planks together face to face, and attach these planks to the rectangle as outlined in the previous step. The ends of these planks must make a tight-fitting 90-degree angle with the inside front and rear planks. Repeat this step for the left side of the rectangle.

Cut one of the remaining planks into 10 smaller boards, with each of these boards being 12 inches long.

Measure the distance between the center of the inside rear joist plank and the center of the inside front joist plank. Trim the remaining planks to match this measurement and place a joist hanger at the end of each plank. Drill into each plank through the holes on each joist hanger and attach the joist hangers into the holes by tightening a wood screw into each hole.

Measure 16 inches from the center of the top edge of the inside right-side joist plank. Place one of the unattached planks 12 inches – or 16 inches on center – away from this plank running parallel to the right side joist. Drill into the front and rear inside joist planks through the holes in each joist and attach the plank to each joist by tightening a wood screw into each hole. Make sure that the distance between the plank and the joist is 16 inches on center along the entire length of the plank.

Place one of the unattached planks 12 inches – or 16 inches on center – away from the plank installed in the previous step. Verify that this plank runs parallel to the previous plank and is level with both the front and back joist planks. Drill into the front and rear inside joist planks through the holes in each joist and attach the new plank to the front and rear joists by tightening a wood screw into each hole. Make sure that the distance between the plank and the joist is 16 inches on center along the entire length of the plank. Repeat this step for the next seven planks.

Place a joist hanger at the end of each 12-inch board. Drill into each board through the holes on each joist hanger and attach the joist hangers into the holes by tightening a wood screw into each hole.

Align the first board with the center post on the right side of the deck frame and install this board between the center face of the inside right joist plank and the joist member immediately to its left. Drill into both joists through the holes in the joist hanger and attach this board to both joists. Repeat this step on each side of each joist member until the 12-inch boards form a center spine for the deck.

Place the first piece of decking material flat across the tops of the joist members and align the front long edge of the decking material piece with the top edge of the front outside joist plank. Drill two holes through the decking material into each joist and insert a deck screw into each hole. Attach the decking material to the joists by inserting a screw into each hole and tightening each screw firmly.

Place the second piece of decking material flat across the tops of the joist members. Butt together the second piece of decking material with the first piece. Drill two holes through the decking material into each joist and insert a deck screw into each hole. Attach the decking material to the joists by inserting a screw into each hole and tightening each screw firmly. Repeat this step with each subsequent piece of decking material until the deck is finished.