Floating/ Island Deck

How to Build a Floating Deck

Floating decks can be set directly on the ground or, preferably, a bed of gravel. But it’s best to support the deck on concrete blocks. This keeps the wood off the ground and away from moisture so the wood stays drier and lasts longer. You can buy special blocks designed for deck support, or you can use standard solid concrete block (the type without holes), which are cheaper and give the deck a lower profile.

What Is a Floating Deck?

Codes and Regulations

You typically do not need a building permit for a floating ground-level deck, but confirm this with your city’s building department before starting your project. In some cases, you may be subject to zoning rules, which govern the size and placement of all structures on a property; your city office will provide guidance.


A deck does not need a handrail or stairs if its walking surface is under 30 inches above the ground. However, it’s best to keep a floating deck as low as possible. Even a fall from a height of 12 inches, or so, can easily twist an ankle or cause more serious injury.


If you need to remove more than a few inches of soil to prepare the site for your new deck call us to have all underground utility lines marked on your property. This is a free service that may take a few days, so call well in advance of starting your project.

What You’ll Need

Equipment / Tools

  • Shovel
  • Rake
  • Tape measure
  • Carpenter’s level
  • Circular saw
  • Drill and drill bits


  • Landscape fabric and gravel (optional)
  • 9 4 x 8 x 16-inch concrete blocks
  • 3 1/2-inch and 2-inch or 2 1/2-inch deck screws
  • 10 Pressure-treated 2x8s (10 feet long)
  • 2 Pressure-treated 2x8s (12 feet long)
  • 22 Pressure-treated 5/4×6 or 2×6 decking boards (12 feet long)