Build an 8×8 play structure with dimensional lumber

How to build an 8×8 play structure out of dimensional lumber.

8 foot by 8 foot play structure around a tree

List of materials and tools for the basic structure (part 1)


  • 4x Pressure Treated (Ground Contact) 4×4 posts, 12′ long (8′ or 10′ possible for shorter platforms)
  • 2x Pressure Treated 2×8 beams, 8′ long
  • 9x Pressure Treated 2×6 Joists, 8′ long (possibly 10 or 11 needed if building box around a tree)
  • 6-8x Pressure Treated 2x4s (6 required for fancy corner braces and assembly bracing, but 8 suggested to make things easier. A few small pieces of scrap 2×4 are very useful for temporarily shelves to hold up boards if you are working alone.)


  • 12x 5/8″ galvanized lag bolts, 4″ long – mounting beams to 4×4 posts
  • 8x 5/16″ galvanized lag bolts, 4″ long – mounting end joists to 4×4 posts
  • 16x galvanized joist hangers (may need more if boxing the tree)
  • 100x 1.5″ galvanized structural screws – joist hangers to beams (can be replaced with 9 gauge galvanized nails if disassembly is not anticipated)
  • 100x 2.5″ galvanized structural screws – joists to beams (can be replaced with galvanized nails)
  • 1lb box of 3″ deck screws (used for attaching bracing together and temporarily mounting beams/joists, not actually part of the finished play structure)
  • Water sealing wood stain (to color/preserve the wood)

Tools Required:

  • Digging tools: Shovel & Post Hole Digger (+ clippers to cut small roots)
  • Wheelbarrow or other way to transport dirt and mix concrete
  • Hoe or concrete mixer, razor knife to open concrete bags
  • Cordless Drill, drill bits, screw drivers
  • Framing Level (4′ or longer suggested), large framing square
  • Tape Measure & pencil,
  • Metal rod (probe for roots), spraypaint or pegs to mark digging locations
  • Adjustable Wrench and/or ratchet driver and sockets for lag bolts
  • Hammer for setting the joist hangers and “persuading” joists into position.
  • Step ladder if you are building a tall platform, or are short.
  • Brush or sprayer for applying wood stain.

List of materials and tools for the flooring and corner braces (part 2)

  • 2x 4×8 exterior grade plywood (for floor)
  • 17x 5.5″ composite deck boards (for floor)
  • 2 lbs of 2″ deck screws
  • Circular saw to clean up the edges of the deck boards (if used)
  • 4x-6x Pressure Treated 2x4s (8′ long) for the corner braces
  • Miter Saw (chop saw), circular saw, or hand saw (for simple corner braces)
  • Compound miter saw (if doing fancy corners)
  • 8x 5/16″ galvanized lag bolts (3″ long) for corner brace to beam/joist connections
  • 8x 5/16″ galvanized lag bolts (4″ long) for corner brace to 4×4 post connections
  • Premium waterproof wood glue for corner brace assembly
  • 2.5″ galvanized nails (or extra 2.5″ structural screws) for corner brace assembly

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