How to Build a Deck With Four Concrete Posts

Installing the Posts

• 1

  Measure and mark the outline of the deck onto the ground with spray paint.

• 2

  Dig a hole into the ground at each corner of the deck for the posts. Use an augur if the holes are more than 1-foot deep. Make the holes slightly wider than the plastic footings for the posts. Dig the holes deep enough to go beneath the frost line. Depending on your location, the frost line can be several feet deep in a cold climate, or a few inches in a warmer climate. Your local zoning board can provide you with the depth of the frost line in your area.

• 3

  Insert the waxed fiber tubes for the posts into the plastic footers. The footers create a wide base, which prevents the posts from sinking into the ground.

• 4

  Place the tubes into the holes, and check them for level. Adjust the tubes if needed, and backfill the dirt around them. Keep the tubes level as you fill the holes.

• 5

  Cut the tubes to the height that you want the posts to extend above the ground, using a utility knife.

• 6

  Place a plastic footing upside-down into each tube. This makes it easier to pour the concrete, as upside-down footings act as a funnel.

• 7

  Fill the tubes and footings with concrete, working a shovel inside the concrete every 8 to 10 inches to remove any air bubbles trapped inside the concrete.

• 8

  Take the plastic footers off of the top of the tubes, then smooth the concrete with a trowel. Allow the concrete to set for the time specified on the packaging.

• 9

  Cut off the excess tubing with a utility knife, if desired.

Building the Deck

• 10

  Cut 2-by-6 boards for the outer frame of the deck, using two boards on each side of the deck. Wear safety goggles when sawing the wood.

• 11

  Nail the two boards you cut for each side of the deck together with galvanized nails so that the outer edge of the frame is doubled up.

• 12

  Nail the outer deck boards together to fit the outline of the deck, using galvanized nails.

• 13

  Place the framing on top of the concrete posts and check it for square by measuring diagonally across the framing in both directions. If the measurements differ, cut a spacer from a 1-by-4 board and place it inside the framing. Check the measurements again, and move the spacer as needed to make the frame square.

• 14

  Mark the outer edges of the deck frame onto the concrete posts, then remove the framing.

• 15

  Place a post base on top of each post, aligning it with the outer edges of the framing. Mark the post base hole onto the concrete, then remove the post base. Drill a pilot hole into the posts with a hammer drill. Place the post base back into position, then slide an anchor bolt into the hole. Tighten the anchor bolts with an impact wrench.

• 16

  Screw galvanized angle brackets to the inside edges of the corners with galvanized screws. This strengthens the corners.

• 17

  Nail galvanized joist hangers to the inside edges of the framing where you're installing the joists for the floor of the deck. Place the joist hangers no more than 1 foot apart.

• 18

  Cut the joists from 2-by-6 boards. Place the joists inside the joist hangers, and drive galvanized nails through the joist hangers and into the joists.

• 19

  Measure the length of the platform -- perpendicular to the joists-- and cut decking boards to fit.

• 20

  Screw the decking boards to the joists and outer frame with galvanized screws.

• 21

  Apply a waterproofing agent to the deck, following the manufacturer's instructions, and allow it to dry. Place the deck into position on the posts, and attach the outer frame to the post bases with galvanized screws.