How to Use Pressure-Treated Wood for a Deck

Measure across the exterior wall of the house the width that you want to make the deck. Mark the wall at each end of the measurement with chalk.

Measure the same distance out from each mark that you made on the wall to the depth that you want to make the deck. If you would like the front of the deck to sit 8 feet from the side of the house, for instance, measure out 8 feet from each mark.

Use a post hole digger to make a hole at this distance from the house in each spot. Cut two 6-by-6-inch pressure-treated posts the height that you want to make the deck plus one-half the post length. For example, if you want the deck to sit 6 feet off the ground, for instance, cut each post 9 feet long with a circular saw.

Place a pressure-treated post into each hole so that the bottom one-third of the post sits below ground level. Mix a batch of concrete and dump the concrete to fill each hold to the top. Center the posts in the holes and let the concrete set for 48 hours.

Add additional posts for the deck if the deck sits further than 8 feet from the house or if the width of the deck extends beyond 8 feet. Place a post every 8 feet or halfway between the other posts if the deck doesn’t use multiples of 8. If the width of the deck is 12 feet, for instance, center a post between the decks at either end.

Cut a piece of metal flashing and a 2-by-6-inch pressure-treated board to the same width that you want to make the deck. Set the flashing against the wall of the house at the height you want the deck to be and line the board up in front of it. Secure the two pieces to the house together by driving a bolt into the materials every 6 inches.

Measure and cut pressure-treated boards to 8 feet (or the distance between the posts in your deck layout) to create a perimeter structure. Secure the boards between the posts by attaching them with four screws at each end. Secure the boards between the posts and the house by screwing them to the board you bolted to the house in Step 6.

Cut pressure-treated boards to the same width as the deck to make joists. Place a cut joist every 12 inches between the sides of the perimeter. Secure the joists with joist hangers so that the edges of the boards line up with the top of the perimeter.

Measure and cut pressure treated boards 2 to 3 inches longer than the distance from the wall of the house to the front perimeter of the deck. Starting at one edge of the deck, lay the boards perpendicular to the joists and secure each board to the joists below with four nails at each joist.