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What a ground-level floating deck costs — the cheapest deck you can build.
With these inputs:
| Result | Value |
|---|---|
| Estimated cost | $1,410 – $2,468 |
| Per square foot | $10 – $17 |
| Deck area | 144 sq ft |
| Supports needed | 16 |
| Decking boards | $576 – $1,008 |
| Framing lumber | $504 – $792 |
| Foundation — 16 deck blocks | $144 – $256 |
| Gravel base | $96 – $192 |
| Fasteners and hardware | $90 – $220 |
A floating deck skips the two most expensive parts of a conventional build: poured footings below the frost line and the ledger connection to the house. That is typically 30 to 45 percent off the total. The trade-off is height — a floating deck sits low, so it only works where the ground is close to the door threshold, and it will move slightly with seasonal frost heave. Ranges are national material estimates and move with local lumber prices; a permit is still required in many places once the deck exceeds a set area or height, so check before you dig.
A floating deck sits on blocks or precast piers instead of poured footings, never touches the house, and in most places stays under the height that triggers a permit. That makes it the cheapest way to get a deck. This prices one out by size, material and foundation type, and shows what you save against a conventional attached build.
A 12 by 12 ft floating deck in pressure-treated pine runs roughly $1,100 to $1,900 in materials if you build it yourself, or about $2,900 to $4,700 with a contractor. Composite pushes materials to around $1,800 to $3,000. The savings against a conventional deck come from the foundation — blocks on gravel instead of poured footings — and from not needing a ledger.
Not in the poured-concrete sense. They sit on precast deck blocks or pier blocks bedded in compacted gravel, which spread the load without going below the frost line. That is what makes them cheap and fast. It also means the deck rides seasonal frost movement rather than resisting it, so expect small shifts in level from winter to summer.
Often not, which is a large part of the appeal, but the exemption is conditional. Most jurisdictions exempt a deck that is under a set height above grade — commonly 30 inches — is not attached to the house, and is under a set area, commonly 200 square feet. Exceed any one of those and it is a normal permitted deck. Always confirm with your own building department; the thresholds vary.
The same as any other deck of the same material — 10 to 15 years for pressure-treated pine, 25 to 30 for composite — provided the frame stays dry and off the soil. The failure mode specific to floating decks is ground contact: keep the joists off the dirt, keep the blocks on gravel that drains, and clear leaves out from underneath so the underside can dry.
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