A floating deck is a popular backyard project that creates a lovely outdoor living space. Floating decks get their name because they sit on top of the ground rather than being attached to the house. This gives them a lightweight, floating appearance.
Building a floating deck is a manageable project for an intermediate DIYer. With proper planning and materials, you can create a beautiful and functional floating deck. This guide will walk you through the entire process from planning to construction. Follow along to learn how to build your own stunning floating deck.
Planning Your Floating Deck
The first step is to plan the design and layout of your floating deck. Consider the size, shape, location, height, and materials. Planning ahead will make the actual building process go smoothly.
Determine the Size
The size of your floating deck will depend on your yard space and what you want to use the deck for. Think about how you plan to furnish the deck and how many people you want it to accommodate. A 12×12 foot deck can fit a table and chairs. A 16×16 foot or larger deck provides more flexibility.
Measure the build area to determine the maximum dimensions for your floating deck design. Make sure to leave enough lawn space around the edges so the deck doesn’t overwhelm the yard. An L-shape or rectangle with a walkway often works well.
Choose the Height
Typical floating deck heights are 8-12 inches off the ground. The height will depend on your preference and needs. Standard stair heights are 6-7 inches. So if you want your deck floor 10 inches high, then build 14-15 inch high stairs.
If you plan to install a floating deck around an existing above-ground pool, build it at the same height as the pool edge for easy access.
Select a Location
Pick a level area of your yard that will accommodate the deck size you want. Check for buried pipes or wires before deciding on the exact placement. Avoid placing your floating deck over underground utilities.
The location should be easily accessible from your home and get ample sunlight if you want to enjoy lounging outdoors. Focus on visibility and safety when choosing the perfect spot.
Choose the Shape
Rectangle and square shapes are the easiest floating deck designs for beginners. You can build the deck flush against the house for stability or use posts and beams to create a freestanding deck.
For a more unique look, consider a polygon, oval, or L-shaped floating deck. Just keep in mind that curved shapes are more challenging to build.
Pick Decking Materials
Pressure-treated lumber is an affordable and durable deck board option. Cedar, redwood, and tropical hardwoods like ipe offer enhanced aesthetics, less maintenance, and longer lifespans.
Composite decking lasts the longest and never needs staining or sealing. Trex and TimberTech are top brands. Expect to pay $30-50 per square foot for quality composite decking.
Select Support Posts
Deck support posts keep the structure secure and level. Use 6×6 inch or 4×4 inch pressure-treated posts buried 1/3 of their height into the ground. Space posts 6-8 feet apart around the perimeter.
For a freestanding floating deck, install an additional post every 6-8 feet in the interior frame. Stain or paint posts to match the deck.
How to Build a Floating Deck Step-by-Step
Now that you’ve completed the planning, it’s time to start building your floating deck. Follow these step-by-step instructions to properly construct your deck frame, install deck boards, add railings, and finish the project.
Gather Materials and Tools
Building a 12×12 foot floating deck requires the following supplies:
- 5-6 6×6″ pressure-treated posts
- 2-3 6×6″ pressure-treated beams cut to 12 feet
- 7-8 2×8″ pressure-treated joists cut to 12 feet
- 100 square feet of 5/4″ x 6″ deck boards
- 1 lb. 3″ wood screws or deck screws
- Exterior wood stain, sealant, paint (optional)
- Post hole digger
- Circular saw or miter saw
- Drill/driver
- Level
- Tape measure
Optional railing supplies:
- Rails – 2×4 or 2×6 boards
- Balusters – 2x2s or composite
- Railing hangers and brackets
- Baluster connectors and nails
Pick up any additional supplies needed for your exact deck size and layout.
Install Deck Posts
The first step is to install 6×6 inch pressure-treated posts around the perimeter of your planned deck. Dig holes using a post hole digger. The holes should be 1/3 the total post height when finished. For example, for a 36 inch tall post, dig 12 inch holes.
Place the posts in the holes and hold plum and square. Backfill the holes with concrete to secure the posts. Use a level on adjacent posts to double check they align properly.
Allow the concrete to fully cure before moving on. All deck posts must be plumb to support the frame and structure.
Attach Beams
Deck beams tie all of the perimeter posts together in a square or rectangular frame. Cut 6×6 inch pressure-treated beams to length and attach them to the top of the posts using sturdy 3-inch deck screws.
Install beams to all four sides, ensuring the frame remains square. Measuring diagonally between posts is the best way to check for square. The measurements should be equal.
For large freestanding decks, add an interior 6×6 beam down the center. Secure it using floor flanges attached to the posts.
Install Joists
Measure the exact distance between your beams and cut 2×8″ pressure-treated joists to length. Position the joists equally spaced 16″ on center across the length of the beams. Use angled deck screws to attach.
Joists run perpendicular to the beams and provide the foundation for laying deck boards. Having proper joist spacing is crucial for structural integrity and prevents sagging.
Add Deck Boards
Now you’re ready for the fun part – installing the surface deck boards! For a basic floating deck, use 5/4″x 6″ boards with the smooth side facing up. This provides nice traction underfoot.
Allow a 1/8″ gap between each deck board to permit drainage and slight expansion. Stagger the ends of the boards to enhance the look. Use two screws placed at angles to secure each board. Work methodically until you’ve covered the entire frame.
Make sure screws are countersunk below the wood surface so they don’t stick up and create a tripping hazard. Acclimate boards on-site for several days before cutting to prevent excessive expansion later on.
Install Railings (Optional)
It’s smart to install a railing around your floating deck for safety and aesthetics. Use pressure-treated 2×4 or 2×6 boards secured to the posts and beams to form the top and bottom rails. Leave a 2-3 inch spacing in between.
Cut and install balusters vertically to fill the railing space. Use composite balusters for low maintenance or poplar for an economical option. Screw balusters in place or use baluster connectors.
For code compliance, space balusters no more than 4 inches apart. Pay attention to deck rail height requirements based on the deck height off the ground. Railings should be 36-42 inches above the deck floor.
Floating Deck Design Tips
Follow these tips to enhance the beauty and functionality of your floating deck:
- Add a pergola or canopy for shade
- Use lighting around the perimeter and steps
- Consider planter boxes along the sides
- Stain the wood a natural tone for visual appeal
- Complement with weather-resistant patio furniture
- Install a fire pit, hot tub, or other backyard features
- Extend the deck with gravel or paver pathways
- Upgrade to composite decking for low maintenance
- Get a building permit if required based on size
Using quality materials and smart design choices will ensure your floating deck remains a cherished backyard addition for years to come.
FAQs About Building Floating Decks
Get answers to some frequently asked questions about constructing floating decks below.
Do you need footings for a floating deck?
No, floating decks do not require concrete footings. The posts sit directly in the ground, making them easier to build. Just backfill the holes with concrete to provide stability when sunk 1/3 into the earth.
How far apart should deck posts be?
For the frame of a floating deck, space 6×6″ posts 6-8 feet apart around the perimeter. Install an additional post every 6-8 feet in the interior if building a freestanding deck not attached to a structure.
Should decking run perpendicular or parallel to the house?
It’s best to run deck boards perpendicular to the house. This allows for better drainage and prevents awkward cuts on the ends. Install the decking boards perpendicular to the joists.
What is the proper deck joist spacing?
For a floating deck less than 18 inches off the ground, space deck joists 16″ on center. This provides sufficient structural support. For decks higher than 18 inches, reduce spacing to 12″ on center.
How do you keep a floating deck from moving?
Securing the 6×6 posts 1/3 their height into the ground with concrete minimizes movement. Additionally, attaching your floating deck tightly to the house perimeter will keep it stable and prevent shifting.
How far apart should deck railing balusters be?
For safety and code compliance, space deck balusters no more than 4 inches apart. This helps prevent children from falling through the railing space. Use a baluster spacing jig to properly space balusters during installation.
Conclusion
Building your own floating deck creates the ultimate backyard relaxation space. Follow the techniques outlined in this guide to properly construct a floating deck frame, install decking boards, add railings, and complete the project like a pro.
With proper planning and preparation, you can create a gorgeous and functional floating deck. Just be sure to check with your local permit office regarding codes and restrictions. Building your own floating deck is an extremely rewarding DIY backyard project that adds beauty, enjoyment, and usable space to your exterior living area for years to come.