How to Build a Deck Using Concrete Blocks

Deck Planning and Layout

• 1

  Find a fairly level area of ground to build the deck. Take a few measurements of the area to see if there is enough room for the deck. Sketch out the proposed deck on graph paper keeping in mind these measurements. This will help determine the amount of material to purchase.

• 2

  Measure and lay out the perimeter of the deck. Hammer a wood stake into the ground at each corner and then connect the stakes with string. Check the lengths of each side to ensure that the stakes are in the correct location.

• 3

  Take two more measurements between the opposite corners. If these lengths are not the same, adjust the stakes.

Position the Blocks and Support Boards

• 4

  Set the blocks in straight rows spaced 24 inches apart. Start at one end and remove the string and corner stakes. Place a block at each corner and evenly space additional blocks within the same row. The blocks must not be more than 24 inches apart.

• 5

  Measure and cut the first 2-by-6-inch support board to size. Place it into the grooves of the blocks and rest a carpenter's level on top of the board to check for level. Use a shovel and add or remove soil under the blocks if necessary.

• 6

  Place and align the next row of blocks 24 inches on center away from the first row. Cut the next 2-by-6-inch support board to size and check for level in a similar fashion. Repeat the process of setting blocks and support boards until you reach the end of the staked area.

• 7

  Take a measurement from the outside of one end board to the outside of the opposite end board. Cut a 2-by-6-inch board to size. Hold it flush with the end support boards and attach the boards together with 3-inch decking screws

• 8

  Butt the ends of the inner support boards against this side board and attach them together with decking screws. Repeat the process for the other side of the deck to complete the deck's frame and support system.

Attach the Top Boards

• 9

  Measure from one end of the deck's frame to the opposite end and cut the first 2-by-6-inch top board to size. Place it across the support boards and along one side. Adjust it so that it is flush with the side and end boards.

• 10

  Attach the top board to each support board with 3-inch decking screws. Repeat the process of attaching the top deck boards as you work your way toward the opposite side.

• 11

  Space the boards 1/4 inch apart if the wood is dry. This helps with drainage and keeps water from settling on top of the deck. If the wood is wet, butt the boards against each other. A gap will develop as the wood dries.