How to Build a Raised Floating Deck: The Ultimate DIY Guide for Homeowners and Pros

Introduction

Imagine stepping out your back door onto a stunning raised floating deck—perfect for barbecues, morning coffee, or just soaking up the sun. No digging deep foundations, no complicated permits, just a sturdy, stylish outdoor space you built yourself. Raised floating decks are a game-changer for homeowners and DIY enthusiasts, offering an affordable, durable way to expand your living area without tearing up your yard. But here’s the catch: one wrong move—like skipping level footings or using the wrong lumber—can turn your dream deck into a wobbly disaster.

In this expert-crafted guide, we’ll show you how to build a raised floating deck from scratch. Whether you’re a homeowner craving a weekend project, a DIYer leveling up your skills, or a pro deck builder refining your process, we’ve got you covered. Expect clear, step-by-step instructions, safety tips, and pro insights on everything from pier blocks to pressure-treated lumber. By the end, you’ll have a deck that’s stable, long-lasting, and envy-worthy—plus the know-how to maintain it for years.

Ready to elevate your backyard? Let’s dig in (well, not literally—this is a floating deck, after all!).

Why Choose a Raised Floating Deck?

A raised floating deck sits above the ground on concrete pier blocks rather than digging into it like a traditional deck with deep footings. This ledger-free design—meaning it doesn’t attach to your house—makes it a favorite for DIYers and pros alike. Here’s why it’s worth your time:

Benefits of a Raised Floating Deck

Easy Installation: No excavation or concrete pouring—just level blocks and a solid frame.
Cost-Effective: Fewer materials and less labor keep costs down (think $1,000-$3,000 vs. $5,000+ for attached decks).
Minimal Ground Disturbance: Perfect for uneven yards or rentals where digging isn’t an option.
Versatility: Build it anywhere—backyards, slopes, or even over rocky soil.
Durability: With proper materials (like pressure-treated lumber), it withstands weather and wear.

Potential Drawbacks

Height Limits: Most stay under 30 inches to avoid needing railings or permits (check local codes).
Less Anchoring: Without a ledger, stability relies heavily on precise leveling and strong footings.
Maintenance: Exposed undersides need regular checks for rot or pests.

Real-World Example: A homeowner in Auckland built a 12×12 raised floating deck for under $1,500 using pier blocks and composite decking. Two years later, it’s still rock-solid—proof this approach works when done right.

Why’s it so popular? It’s a low-commitment, high-reward project that transforms your outdoor space without breaking the bank or your back.

Planning & Materials Needed

Success starts with preparation. Here’s how to plan your raised floating deck and gather the right tools and materials.

Step 1: Plan Your Deck

Size: Measure your space—10×10 or 12×12 feet are popular for small yards; scale up for bigger areas.
Height: Keep it under 30 inches (750mm) to dodge railing requirements in most regions.
Location: Pick a flat or gently sloping spot with good drainage. Avoid trees or utility lines.
Permits: Check local building codes—some councils require approval for decks over 1.5 meters high or near boundaries.

Pro Tip: Sketch your design with exact dimensions and footing placement. A simple grid on graph paper works wonders.

Tools

Tape Measure: For precise sizing and spacing.
Level (4-foot): Ensures a flat frame—critical for stability.
Circular Saw: Cuts lumber to size.
Drill & Bits: Drives screws and sets anchors.
Shovel: Clears grass or levels ground slightly.
String Line & Stakes: Marks your layout.
Safety Gear: Gloves, goggles, and sturdy boots.

Materials

Concrete Pier Blocks: 4×4 or adjustable versions—1 per 4-6 feet of deck span.
Pressure-Treated Lumber: 4×4 posts, 2×6 or 2×8 joists, and beams (treated for rot resistance).
Decking Boards: Cedar, redwood, or composite for the surface.
Galvanized Fasteners: Deck screws (2.5-3 inches) and joist hangers for secure joints.
Post Anchors: Metal brackets to connect posts to blocks.
Gravel: Optional, for drainage under blocks.
Landscape Fabric: Prevents weeds under the deck.

Cost Estimate: A 10×10 deck might run $800-$1,200—pier blocks ($5-$10 each), lumber ($300-$500), decking ($400-$600), and fasteners ($50-$100).

Step-by-Step Guide to Building a Raised Floating Deck

Time to build! This process assumes a 12×12 deck under 30 inches high—adjust as needed. Expect 2-3 days of work, depending on skill level.

Step 1: Mark and Prepare the Site

Outline the Deck: Drive stakes at the corners and run string lines to mark the perimeter. Measure diagonally to ensure it’s square (equal diagonals = square).
Clear the Area: Remove grass, rocks, or debris with a shovel. You’re not digging deep—just skimming the surface.
Add Gravel (Optional): Spread 2-3 inches of gravel for drainage, especially in wet climates.

Safety Note: Call your utility company to check for buried lines before disturbing soil.

Step 2: Set the Pier Blocks

Space the Blocks: Place one every 4-6 feet along the perimeter and interior (e.g., 9 blocks for a 12×12 deck).
Level Them: Dig shallow holes, set blocks, and use a 4-foot level across each row. Adjust with gravel or soil until all are even.
Check Alignment: Run string across the tops—every block should touch it.

Troubleshooting: Uneven blocks? Shim with flat stones or dig deeper. Wobbly blocks mean an unstable deck.

Step 3: Build the Deck Frame

Cut Posts: Trim 4×4 posts to your desired height (e.g., 24 inches). Attach them to pier blocks with post anchors and galvanized screws.
Install Beams: Lay 2×8 beams across the posts, securing with screws or joist hangers. Double up beams on longer spans for strength.
Add Joists: Space 2×6 joists 16 inches apart (on center) perpendicular to beams. Attach with joist hangers and screws.

Pro Tip: Pre-drill holes to prevent wood splitting—especially with pressure-treated lumber.

Step 4: Lay the Decking Boards

Cut to Fit: Measure and trim decking boards to span the frame. Leave a 1/8-inch gap between boards for drainage.
Fasten Securely: Use two screws per joist (about 1 inch from edges). Drive them flush, not countersunk, to avoid water pooling.
Finish the Edges: Trim overhanging boards with a circular saw for a clean look.

Troubleshooting: Warped boards? Clamp them straight while screwing, or flip them to the flatter side.

Step 5: Inspect and Test

Check Stability: Walk across the deck—any bounce or creaks mean loose joints or uneven footings. Tighten screws or adjust blocks.
Level Test: Place a level on multiple spots. Adjust posts if it’s off by more than 1/4 inch.
Water Test: Hose it down to ensure drainage—no pooling should occur.

Case Study: A DIYer in Hamilton built a 10×14 raised floating deck with cedar boards and adjustable pier blocks. After leveling issues on a slope, they added extra blocks—problem solved, and it’s hosted parties for three years running.

Step-by-Step Guide: How to Build Deck Handrails

Let’s break this down into six detailed steps. For this example, assume a 12-foot deck section with a 36-inch handrail height—adjust as needed for your project.

Step 1: Gather Materials & Tools

Preparation sets the stage. For a 12-foot section, you might need:

2 pressure-treated 4×4 posts (8 ft long, to be cut).
10-12 2×2 balusters (36 inches each, pre-cut or trimmed).
2×4 top and bottom rails (12 ft long).
Hardware: 50 stainless steel screws, 4 lag bolts with washers, 2 post anchors, 4 handrail brackets.

Lay everything out on a tarp or workbench. Check your saw blade’s sharpness—dull blades tear wood. Wear goggles and gloves from the start; safety isn’t an afterthought.

Step 2: Measure & Mark the Post Locations

Accuracy here prevents a domino effect of errors. Here’s the process:

Height: Local codes often require 36 inches minimum (check NZBC F4 or your council). Posts should extend 6 inches above this for rail attachment—cut them at 42 inches from the deck surface.
Spacing: Place corner posts at each end of the 12-foot run. Add an intermediate post at 6 feet if the span feels flimsy (max 8 feet between posts is standard).
Marking: Use a pencil to mark post bases on the deck’s rim joist or surface. A chalk line ensures a straight run; a carpenter’s square keeps corners crisp.

Measure twice—once from each end—to confirm symmetry. For stairs, mark posts at the top and bottom, adjusting for slope.

Step 3: Install the Deck Posts

Posts are your handrail’s backbone. Here’s how to set them up:

Cut Posts: Trim 4x4s to 42 inches (or your code height + 6 inches). Use a circular saw with a guide for straight cuts.
Secure Posts: For rim joist mounting, drill two ⅜-inch holes per post and fasten with lag bolts and washers. For surface mounting, bolt post anchors to the decking, then screw posts into anchors.
Check Plumb: Place a level on two adjacent sides of each post. Shim or adjust until perfectly vertical, then tighten fully.

Pro Tip: Pre-drill bolt holes to avoid splitting—wood hates surprises. For elevated decks, tie posts into the structural frame, not just the deck boards, for code compliance.

Step 4: Attach the Top & Bottom Rails

Rails connect the posts and prep for balusters. Follow these steps:

Cut Rails: Measure the exact distance between posts (e.g., 12 feet). Cut 2x4s to fit. For a sleek look, miter ends at 45 degrees with a miter saw.
Bottom Rail: Position it 1-2 inches above the deck surface to allow water runoff. Secure to posts with handrail brackets or angled 2½-inch screws.
Top Rail Base: Mount a 2×4 flat between posts at 36 inches (or your required height). Use brackets or screws every 12 inches for strength.

Use a level to ensure rails are horizontal—slanted rails look amateurish and feel unstable.

Step 5: Install the Balusters or Spindles

Balusters fill the gaps, making your handrail safe and stylish:

Spacing: Mark the bottom rail every 4 inches (or less) using a 3½-inch spacer block for consistency. For 12 feet, you’ll need about 11 balusters.
Cut Balusters: Trim 2x2s to 34 inches (top rail height minus bottom rail gap). A miter saw ensures uniform lengths.
Secure: Attach each baluster with two screws per end—one into the top rail, one into the bottom. Pre-drill with a ⅛-inch bit to prevent splitting.

Check plumb with a level as you go. Misaligned balusters throw off the whole look—fix them early.

Step 6: Attach the Handrail & Secure Everything

The handrail caps it off:

Cut Handrail: Use a 2×4 or pre-shaped handrail piece, cut to 12 feet. Bevel edges with a sander for a comfy grip.
Attach: Center it atop the posts and top rail base. Fasten with 3-inch screws or bolts every 12-18 inches, driving them into the posts for max strength.
Finish: Sand rough spots with 120-grit sandpaper. Apply a weather-resistant finish—penetrating oil for wood, nothing for composite or metal.

Test by leaning on it—it should feel rock-solid. Tighten any loose screws or bolts.

Deck Build And Contact US

Tips for Stability, Longevity & Weather Protection

A great deck lasts decades with the right care. Here’s how to make yours bulletproof:

Stability Boosters

Extra Blocks: Add mid-span supports if you feel flex—better safe than shaky.
Diagonal Bracing: Screw 2x4s diagonally under the frame on larger decks to reduce sway.
Quality Fasteners: Galvanized or stainless steel resists rust—cheap screws fail fast.

Longevity Hacks

Seal the Wood: Apply a water-repellent sealant to pressure-treated lumber every 2-3 years.
Ventilation: Keep 6-12 inches of clearance under the deck to prevent rot.
Weed Control: Lay landscape fabric under the deck to stop growth.

Weather Protection

Slope Slightly: Angle the deck 1/8 inch per foot away from the house for runoff.
UV Protection: Composite decking or a UV-resistant stain fights sun damage.
Winter Prep: Clear snow promptly to avoid excess weight.

Real-World Example: A pro builder in Christchurch used double beams and sealed cedar on a 16×20 floating deck. Five years later, it’s weathering storms like a champ.

Maintenance & Safety Considerations

Keep your deck safe and stunning with these essentials:

Maintenance Routine

Annual Check: Inspect for loose screws, rot, or wobbly blocks—tighten or replace as needed.
Clean Regularly: Sweep debris and hose off dirt. Scrub with mild soap yearly to remove mildew.
Reseal: Refresh sealant every 2-3 years to protect against moisture and UV rays.

Safety Musts

Weight Limits: A 2×6 joist frame handles 50 lbs per square foot—don’t overload with heavy furniture.
Railings: Add them if over 30 inches high or near a drop-off (check local codes).

Non-Slip Surface: Apply anti-slip tape or a textured stain in wet climates.

FAQs About Building a Raised Floating Deck

Q: How much does it cost to build a raised floating deck?

A 10×10 deck averages $800-$1,200 with basic materials. Larger or premium builds (e.g., composite decking) can hit $2,000-$4,000.

Q: Do I need a permit for a raised floating deck?

Maybe—decks under 30 inches often skip permits, but check your local council. Over 1.5 meters or near boundaries might need approval.

Q: How long does it take to build?

A 12×12 deck takes 2-3 days for a DIYer with moderate skills—faster with help or experience.

Q: Can I build a floating deck on a slope?

Yes! Use adjustable pier blocks or longer posts to level it—extra bracing helps on steep grades.

Q: What’s the best wood for a floating deck?

Pressure-treated pine is affordable and rot-resistant. Cedar or redwood adds beauty; composite skips maintenance.

Choosing Materials: Wood vs. Composite

Pressure-Treated Lumber: Cheap ($1-$2 per foot), durable, but needs sealing.
Cedar/Redwood: Naturally rot-resistant ($2-$4 per foot), gorgeous, but pricier.
Composite: Low-maintenance, weatherproof ($4-$6 per foot), ideal for busy homeowners.

Pro Tip: Mix and match—use treated lumber for the frame and composite for decking to balance cost and upkeep.

When to Call a Professional

DIY not your vibe? Hire a pro if:

Complex Terrain: Steep slopes or rocky soil need expert leveling.
Large Scale: Decks over 20×20 demand precise engineering.
Code Confusion: Pros navigate permits and inspections seamlessly.

Conclusion: Build Your Dream Deck Today

A raised floating deck isn’t just an upgrade—it’s a lifestyle boost. With this guide, you’ve got the tools, steps, and insider tips to craft a sturdy, stylish outdoor haven. From laying pier blocks to screwing down decking boards, every move builds your skills and your backyard’s value. Don’t let uneven ground or budget woes hold you back—start small, build smart, and enjoy the rewards.

Ready to make it happen? Grab your tape measure and get started. Or, for flawless results, call My Homes Decking Expert at +64 22 315 8987 for a free quote today. Your perfect deck awaits!