How to Build an Exterior Wood Deck

Draw a scale plan for the wood deck on graph paper. Use a specific number of boxes on the graph paper to represent a foot of the deck, and space the posts that support the deck every eight to 10 feet. Connect the posts on the plan with beams around the entire perimeter of the deck, space joists every 12 to 16 inches across the beams, and space the floorboards of the deck so that they have approximately ¼ to ½ inch of space between them.

Recreate the measurements from the plan on the ground. Place a wood stake at every location where you need to place a post, and tie strings between the stakes.

Measure and cut a 2-by-6 board and a piece of metal flashing to the length that you want to make the deck. Measure up from the ground every one to two feet to the height where you want the deck to touch the house, lay the flashing directly against the house at this height, and lay the wood board so that it lines up against the front of the flashing. Drill a pilot hole through the wood and flashing and into the side of the house every six inches, and drive bolts through the pilot holes to secure the materials.

Use a post hole digger to make a hole in the ground at the position of each stake. Make the hole a depth that is equivalent to one-third the distance from the ground to the bottom of the deck. Place a 6-by-6-inch post that is long enough to have the bottom third buried with the top still reaching the height that you want the deck into each hole. Mix concrete in a wheelbarrow, pour the concrete around each post to secure it, and let the concrete dry for at least 24 hours.

Cut 2-by-6 wood boards down to 8 or 10 feet in length, making the length of the boards the same as the distance between the posts. Attach one board between each set of posts, and between the posts closest to the wall and the board attached to the house with four 4-inch wood screws to create a wood border around the perimeter.

Set 2-by-6 boards every 12 to 16 inches between the front of the wood border and the wood attached to the house or between the sides of the wood perimeter, depending upon how you want the floorboards to lay on the deck, and secure the joists with joists hangers. If you want the floorboards to go from side to side across the deck, lay the joists so that they extend outward from the house. If you want the floorboards to lay outward from the house, lay the joists parallel to the side of the house.

Place the floorboards of the deck perpendicular to the joists. Use screws to attach the floorboards to the deck and cover the floorboards with waterproof sealant for a long-lasting surface.