Step 1: Getting Started/Examining the Plans

From the plans found on our website, locate the Framing Plan. This is the most useful page for building the Octagonal Deck. In these instructions, we will be using a 12' Octagonal Deck as an example. Slight modifications will need to be made for larger or smaller octagonal decks.

Start by building the core rectangular section of the deck. To build the core, use two 2"x6" support boards, two 2"x6" end boards, a 4"x4" post, and the four corner Dek-Block® piers.

Block Plan Example	Framing Plan Example	Decking Plan Example

Step 2: Place the two corner Dek-Block® piers

Begin by positioning two corner Dek-Block® piers directly on the soil. If the ground is sloped, remove only the top soil directly under the block so that the block sits level. Be sure to verify that the distance between the blocks is accurate, by referencing the dimensions on the plan. The outside edge of the finished deck will extend out past the center of the Dek-Block® piers by 13 1/2" on both sides.

Deckman's Comments

There is no such thing as a perfectly level yard. I get a lot of calls and e-mails from people who try not to use 4x4 posts. The best tip I can give anyone building a deck is to use 4x4 posts, even if you only have a very slight slope of the yard. Leveling every block to each other is very difficult and time consuming. If you need a 2-1/4" 4x4 post, cut a 2-1/4" 4x4 post. It takes about 90 seconds to measure and cut a 4x4 post, and the post only weighs a few pounds. Moving a block up or down to an exact measurement takes 4 to 10 minutes per block. Remember, these are 42 lbs. blocks you're working with. Save your back for carrying the cooler onto the deck when you're done.

Don't spend too much time leveling the Dek-Block® piers. The block does not need to be perfect. The block can be leveled with only your eye. Position the block so that it looks level. If you place a level in the block, you're spending too much time on it. Any slight difference will be made up with the 4"x4" post. You also want to make sure the Dek-Block® piers are sitting FLAT. You don't want any rocking of the piers on the ground.

Step 3: Level the support board.

Locate the highest corner Dek-Block® pier. Position a 2"x6" support board in or above this first block to your desired height. If the entire deck will be elevated, you will need to have a 4"x4" post in the first block.

If the entire deck is elevated you will need to find the height of the first 4"x4" post to determine your starting point. First determine your reference point for the top of the deck surface. This may be the threshold of a door or a point on the siding. Mark a line level with this point that will extend near the first block. From this line, hold a level out over the block and measure from the bottom of the level to the pocket of the block. From this measurement, subtract the thickness of the surface board and the thickness of the support board (1 1/2" + 5 1/2" = 7"). Cut the first 4"x4" post at this measurement and continue with the directions.

Next, place a 2"x6" support board in the slot of the Dek-Block® pier or on the 4"x4" post, and extend over the second corner Dek-Block® pier. Using a level on top of the 2"x6" support board, measure the distance from the bottom of the 2"x6" support board to the bottom of the pocket in the Dek-Block® pier. Cut a 4"x4" post to length and position the 2"x6" support board on top. Verify that the 2"x6" support board is level, don't attach the 2"x6" support board to the 4"x4" post yet.

If the deck is placed next to a door, the deck should be between 1/2" and 1" below the door's threshold. Or if you want a step up to the door, the deck should be between 6-7 inches below the door. You don't want anything between 1-6 inches; this will create a trip hazard.

Step 4: Level the opposite side.

Place the two remaining corner Dek-Block® piers. Using the same width between Deck-Block® piers as the first row, measure using the dimensions on the plan.

Remove the first support board. Temporarily position a 2"x6" end board on top of the first row's 4"x4" post or block, and extend to the opposite corner block. Then, using a level on top of the 2"x6" end board, measure the distance from the bottom of the 2"x6" end board to the bottom of the pocket of the Dek-Block® pier. Cut a 4"x4" post to length and position the 2"x6" end board on top. Verify that the 2"x6" end board is level. When level, remove the end board and repeat for the opposite side.

Step 5: Square the Frame.

Place a 2"x6" support board on top of each row of Dek-Block® piers. Attach 2"x6" end boards to the support boards using two 2 1/2" deck screws at each connection. The 2"x6" end boards will extend past the two 2"x6" support boards. Make sure the end board extends equally on either side. Using a level as a guide, ensure that both end boards and both support boards are level. Measure the diagonal distance from opposite corners. Adjust the support boards and Dek-Block® piers until the diagonal distance between opposite corners is EQUAL. After the deck is square and level in all four directions, attach the 2"x6" support boards to the 4"x4" posts using two 2 1/2" deck screws at an angle from each side (toe-screw).

Toe-Screwing Supports

Step 6: Attach Remaining 2"x6" Support Board.

Position and attach the remaining 2"x6" support board to the end boards using the dimensions provided on the plan. Use two 2 1/2" deck screws to attach the support board to the end board.

Step 7: Position remaining Dek-Block® Piers.

Using the frame as a guide, position the remaining Dek-Block® piers directly beneath the frame using the dimensions provided on the plan. The blocks to the outside of the deck should be 12 inches in from each end.

Go down each row measuring the distance between the 2"x6" support board and the Dek-Block® pier. Cut 4"x4" posts to length and position between the support board and the Dek-Block® pier. Repeat until all 4"x4" posts are cut and positioned. Secure all support boards and 4"x4" posts using two 2 1/2" deck screws at an angle (toe-screw) from each side.

Deckman's Comments

Don't get caught up in the small dimensions. You want to position the blocks accurately, but there's no need to be exact. There is a lot of "play" in the spacing between the piers. As long as you don't exceed 5 ft. between blocks, the deck will be fine. It's fine to have one row spaced at 3 ft. 10 inches from the one block and 4 ft. 2 inches from the other block. However, the deck will look better if all the piers are aligned in a straight row.

This is a great job for 2 people. Have one person measure the height for the 4"x4" post and another person cut the post. Go down the rows measuring and cutting all of the posts, then place all the posts at the same time. This may require lifting the frame up slightly in order to get the post under the support board.

If you are building by yourself, go down the rows measuring the height for the 4"x4" posts. Write the measurement on a piece of paper and on the side of the support board. Cut all the 4"x4" posts at once and then position.

Step 8: Placing the outside supports.

Find the location of the outside support boards and Dek-Block® piers. These will be centered between the existing rectangular core frame.

Extend a temporary 2"x6" support board from the existing rectangular core frame over the outside Dek-Block® piers. Using a level as a guide, measure from the bottom of the board to the bottom of the pocket of the Dek-Block® pier . From this measurement, subtract the thickness of the support board (5 1/2" ). Cut the 4"x4" post at this measurement. Repeat for the three remaining blocks.

Place the 4x4 posts in the outside Dek-Block® piers. Set the 2"x6" support boards on top and verify that the support board is level from block to block and the existing frame.

Step 9: Attach the angled sides.

Using the dimensions found on the plans, cut the four angled 2"x6" end boards. Both ends of these boards will have a 45 degree angle cut. Secure both ends to the existing frame with two 2 1/2" deck screws at each connection.

Step 10: Place remaining support boards.

Along the angled end boards, find the locations for the remaining support boards. (You will NOT find the dimensions for these boards on the plan. This is intentional. Due to slight differences in construction methods, the lengths of these remaining supports may vary.) Before cutting anything, place the 2"x6" support board on top of the 2"x6" angled end boards at the found location. Using a pencil from below, mark the angle and location of the cut. Next, cut both ends with a 45 degree angled cut.

After cutting the remaining support boards, position into the frame and secure with two 2 1/2" deck screws at each connection.

Step 11: Place remaining Dek-Block® piers.

Using the frame as a guide, position the remaining Dek-Block® piers directly beneath the frame using the dimensions provided on the plan. The blocks to the outside of the deck should be 12 inches in from each end.

Go down each row measuring the distance between the 2"x6" support board and the Dek-Block® pier. Cut 4"x4" posts to length and position between the support board and the Dek-Block® pier. Repeat until all 4"x4" posts are cut and positioned. Secure all support boards and 4"x4" posts using two 2 1/2" deck screws at an angle (toe-screw) from each side.

Step 12: Attach the Decking.

Starting from one side of the deck, attach the first 2"x6" surface board flush to the edge of the deck. Along the angled section of the deck, allow the 2"x6" surface boards to extend past the angled end boards by at least one inch. Secure with two 2 1/2" deck screws at the connection of each support board. If the surface boards are pressure treated and wet, position the boards flush against each other (edges touching). Within a few days, a small gap will form as the boards dry and shrink. If the surface boards are cedar, redwood, or composite decking, leave a 1/8" gap between the surface boards.

After all surface boards are secured, use a chalk line to mark a line that follows the angled end boards. With a circular saw, trim the overhanging 2"x6" surface boards so that they're flush with the the angled end boards.