How to Build an Octagonal Deck

Step 6: Finish Deck Foundation

As in Step 5 the ODD numbered posts are framed to create a rectangle that intersects the rectangle of the EVEN posts. Follow the image, screw the pressure treated lumber in place and then double up the rectangles. What we have now is an 8 pointed polygon which is the deck foundation. Each Point or Vertex of the polygon will support a deck joist. (If you start the rectangle with the ODD numbered posts, it doesn't matter, as long as you end up with the 8 pointed polygon.)