A floating deck — low, freestanding, and not attached to the house — is the fastest path to a backyard deck in most GTA cities because it stays under the building permit thresholds. Keep it under 24" (600mm) above grade AND under 108 sq ft (10 m²) and you can typically build without a permit in Toronto, Mississauga, Brampton, or Markham. This guide focuses specifically on that permit-exempt floating platform build.
This is a different project from a full attached or elevated deck. No ledger, no concrete footings, no inspections, no waiting 4–6 weeks for plan review. If you want the complete framing and footing deep-dive for larger builds, see our comprehensive deck build guide. What follows here is everything you need for the permit-exempt floating platform — from layout stakes to the final deck board.
💡 The Permit-Exempt Zone in Most GTA Cities
Deck surface under 600mm (24") above grade at all points AND total footprint under 108 sq ft (10 m²). A 10×10 ft (100 sq ft) floating deck sitting 12–18" above level ground = typically permit-exempt. ALWAYS confirm with your municipality before building — rules vary and lots with slopes can push deck height above 600mm even for ground-level builds. See our full Ontario deck permit guide for municipality-by-municipality thresholds.
Why Choose a Floating Deck?
For a first-time deck builder — or anyone who wants a functional outdoor platform without the complexity of a full permitted build — a floating deck offers a genuinely compelling set of advantages:
- No building permit (if under thresholds)
- No footings required in most cases — deck blocks on compacted gravel handle the job
- No ledger attachment to house — no flashing, no structural engineering, no house wall penetrations
- Faster to build: a 10×10 floating deck can be completed solo in a weekend
- Can be disassembled and relocated if you sell the house or want to move the deck
What You'll Need
🪵 Materials (10×10 ft PT Deck)
- 9 deck blocks or compacted gravel base pads
- 3 pressure-treated 4×4 or 4×6 beams, 10 ft
- 11 pressure-treated 2×6 joists, 10 ft
- 15 pressure-treated 5/4×6 deck boards, 10 ft
- 2.5" or 3" composite deck screws (approx. 2 lbs for a 100 sq ft deck)
- Joist hanger hardware + structural screws
🔧 Tools
- Circular saw
- Drill/driver
- Measuring tape and chalk line
- Level (4 ft) and string lines
- Rubber mallet (for deck blocks)
- Safety glasses
GTA Materials Pricing (2026)
Pressure-treated lumber prices in the GTA stabilized through 2025 and into 2026 after the volatility of earlier years. Here's what to expect at GTA lumber yards and big-box stores for a 10×10 floating deck build:
- Pressure-treated 5/4×6 deck boards (10 ft): $8–$13 each
- PT 2×6 framing lumber (10 ft): $12–$18 each
- PT 4×6 beam (10 ft): $25–$40 each
- Deck blocks (9 needed for 10×10): $8–$15 each = $72–$135 total
- Composite deck screws (1 lb box): $25–$35
- Total materials for a 10×10 PT floating deck: $450–$750
For the full cost breakdown — including labour estimates and upgrade options like composite decking — see our deck building cost in Toronto guide.
How to Build a Floating Deck: Step by Step
Plan Your Layout and Confirm Height
Measure your intended location. Stake the four corners. Run string lines to establish the deck outline. Measure from the ground to your string at all points — this represents your approximate deck height above grade at each corner. Keep this under 24" (600mm) at all points, including on sloped areas. If any corner exceeds 24", consider moving the deck to flatter ground, lowering the deck design height, or consulting your municipality about permit requirements. This height check takes 20 minutes and is the most important step in the planning phase.
Prepare the Ground
Remove sod and organic material under the deck footprint to a depth of 3–4 inches. Fill with compacted gravel (clear crush, 19mm) — this prevents settling, improves drainage, and eliminates the weeds that otherwise grow under your deck. Compact with a plate compactor (rental: $80–$120/day) or hand-tamper. A 4–6" compacted gravel base is the foundation for deck blocks. Don't skip this step — organic material underneath a deck will decompose and cause uneven settling within a few years.
Set Deck Blocks
For a 10×10 deck, use 3 rows of 3 deck blocks each (9 total). Set the outer row first. Place each block on the gravel base. Use a 4 ft level and string lines to get all blocks level to each other. Minor adjustments: add or remove fine gravel under individual blocks. This step requires patience — all subsequent steps depend on the blocks being level. Check level diagonally as well. Deck blocks will shift slightly with Ontario's frost cycles, but a properly levelled and gravel-supported foundation minimizes seasonal movement.
Install Beams
Set three 10 ft beams across the blocks, running in one direction. Level each beam. Secure to deck blocks — most deck blocks have a groove that accepts the beam; use metal post-to-beam connectors for added stability in the GTA's frost heave environment. Check that all three beams are in the same plane (level with each other in all directions) before proceeding.
Install the Joist Frame
At 90° to the beams, install the outer rim joists at each end of the beams (perpendicular). Install interior joists at 16" on-centre, using joist hangers. Check that the frame is square by measuring diagonals — equal diagonals mean square corners. The frame should feel rigid before adding any decking. If the frame rocks or feels loose, recheck your beam levelling and deck block connections before moving on.
Install Decking Boards
Snap a chalk line along the starting edge (typically the board closest to the house or the most visible side). Install the first board perfectly straight with a 6mm gap from any structure or post. Work outward, spacing boards 3–5mm apart — use a 16d nail as a spacer, or composite spacers. Drive 2 screws per board per joist. Pre-drill near board ends to prevent splitting in pressure-treated lumber. Allow a 3/4" overhang past the rim joist on all exposed sides for a clean finished edge. Cut the final board to fit if needed. Do not butt boards tight — the spacing allows water to drain and wood to expand seasonally.
💡 Finishing and Maintenance
Let PT lumber dry and weather 60–90 days before staining — fresh pressure-treated lumber repels most finishes. Apply a penetrating deck stain/sealer every 2–3 years to protect from GTA's freeze-thaw cycles. Even a floating deck is subject to Ontario's weather extremes. See our guide on how to stain your deck for product recommendations and technique.
Cost Summary: 10×10 Floating Deck (GTA, 2026)
| Item | Low | High |
|---|---|---|
| Deck blocks (9) | $72 | $135 |
| PT framing lumber (beams + joists) | $200 | $400 |
| PT deck boards (15 at 10 ft) | $120 | $200 |
| Hardware + screws | $80 | $150 |
| Gravel (compacted base) | $40 | $100 |
| Total materials (10×10 PT floating deck) | $512 | $985 |
This budget does not include tools (most are standard homeowner tools) or the optional plate compactor rental. A composite decking upgrade adds $300–$600 to the material cost for a 10×10 footprint. For a larger deck or a complete labour + materials estimate, see our deck building cost in Toronto guide.
Frequently Asked Questions
Do I need a permit for a floating deck in Toronto in 2026?
No permit is required in Toronto for a floating deck that is under 108 sq ft (10 m²) in total footprint AND has the deck surface no higher than 24" (600mm) above grade at any point. A 10×10 ft floating deck sitting 12–18" above level ground typically qualifies as permit-exempt. However, you must still comply with zoning setback requirements — the deck cannot be built too close to your property lines. Always confirm with the City of Toronto building department before starting. For full details on permit thresholds across GTA municipalities, see our Ontario deck permit guide.
Can I use deck blocks instead of concrete footings for a floating deck in Ontario?
Yes. For a permit-exempt floating deck (under 24" above grade, under 108 sq ft), deck blocks placed on a compacted gravel base are the standard approach and do not require concrete footings. Deck blocks are precast concrete pads with a groove or saddle for the beam. They sit on the surface rather than being embedded below the frost line, which means they will move slightly with Ontario's freeze-thaw cycles — this is expected and acceptable for a low, freestanding platform deck. A good compacted gravel base minimizes movement significantly.
How high above the ground can a floating deck be without a permit in the GTA?
In most GTA municipalities — including Toronto, Mississauga, Brampton, and Markham — the threshold is 600mm (24 inches) above grade at any point on the deck surface. If any part of the deck surface exceeds 600mm above the ground directly below it, a permit is required. On a sloped lot, even a ground-level deck can push past 600mm on the downhill side. Always measure at the highest point of the deck relative to the ground, not just at the house end.
Can I build a floating deck on a slope in my GTA backyard?
You can, but slopes are where permit-exempt floating decks get complicated. As the ground drops away from the high side of the deck, the deck surface rises above grade. Even a modest 6" drop across 10 feet can push the low-side deck height close to or above 24". Before building on a slope, run string lines and measure the deck surface height above grade at every corner and midpoint. If any point exceeds 600mm (24"), you'll need a permit — or you'll need to reposition the deck to flatter ground. Our comprehensive deck build guide covers sloped-lot framing strategies for permitted builds.
How long does a pressure-treated floating deck last in Ontario?
A well-built pressure-treated floating deck typically lasts 15–25 years in Ontario's climate with proper maintenance. The decking boards are the first component to show wear — expect 15–20 years before replacement is needed if you apply a penetrating stain/sealer every 2–3 years. The framing (beams and joists) lasts longer, often 20–30 years, because it is less exposed to direct UV and rain. Deck blocks and a compacted gravel base hold up indefinitely. Ontario's freeze-thaw cycles are the primary enemy — keeping water out of the wood grain with regular sealing extends service life significantly. See our guide on how to stain your deck for the right products and schedule.