Floating & Ground-Level Deck Guide (2026)

It depends entirely on whether your ground freezes, and this is the rule people most often get wrong about floating decks. In warm, no-freeze regions, concrete deck blocks set on level compacted gravel are usually acceptable and are the reason a floating deck can go up in a weekend — $8 to $12 each, no excavation, no pour. In cold climates most jurisdictions still require footings below the frost line under IRC R403.1.4 even though the deck is freestanding, because frost heave does not care what the deck is attached to: water freezing under a block lifts it, the thaw drops it somewhere slightly different, and a frame that was level in October is racked by March. Buried sonotube piers run $95 to $175 each and are what separates a five-year deck from a thirty-year one in a freeze climate. Confirm with the building department before choosing.

Often not, which is a large part of the appeal — but the exemption is narrower than people assume and it is local. The common pattern is that a deck is exempt when it is under 200 square feet, no more than about 30 inches above grade at any point, freestanding rather than ledger-attached, and not serving a required exit door. A floating deck satisfies the attachment test by definition, so the size, height and doorway tests are the ones to check. Cross any single one and a permit is normally required. Two things worth being clear about: the thresholds genuinely vary between jurisdictions, so this is a phone call rather than a web search, and an exemption from permitting is not an exemption from code. The structure still has to be built to standard, and it will still be looked at if the house is ever sold or inspected.

The terms overlap so heavily that most people use them interchangeably, but they describe different things. Floating means freestanding — the deck is not attached to the house with a ledger and carries all of its load on its own piers. Ground-level means low to grade, usually under about 30 inches, which is the height at which IRC R312 stops requiring a guard. Most ground-level decks are also floating, because once you are that low there is little reason to attach to the house, and most floating decks are also low. The distinction matters when only one is true: a freestanding deck built high still needs guards and, in most places, a permit, while a low deck attached with a ledger still needs the ledger flashing and the lateral-load anchors that floating decks avoid.

Materially less than an attached deck of the same size, for three separate reasons: there is no ledger to flash and anchor, there is often no permit, and in warm climates there may be no frost-depth footings. Surface material runs about $1.95 per linear foot for pressure-treated pine, $3.40 for cedar and $3.80 for mid-tier composite. Support is the variable that moves the total most: $8 to $12 per concrete deck block, $45 to $65 for a pre-cast pier cap with a post anchor, or $95 to $175 per buried sonotube pier with concrete. A small block-supported pressure-treated platform therefore lands well under a comparable elevated deck, while the same deck on frost-depth piers in a cold climate closes much of that gap. DeckMath's floating-deck calculator prices your own dimensions across the three support types.

No, and it removes what is statistically the most common reason attached deck plans fail inspection. Lateral-load anchors such as the Simpson DTT2Z exist to tie a deck back into the house framing so it cannot pull away from the building, and a floating deck has nothing to pull away from. What a floating deck does need instead is resistance to racking — side-to-side sway, since there is no house to lean on. That comes from diagonal bracing between posts and piers, or, on a very low deck, simply from close pier spacing, because the lower the frame the less leverage wind and footsteps have to move it. Do not skip bracing on a floating deck that stands high enough to have visible posts; a frame that racks progressively loosens every connection in it.

In a warm climate and on a small platform, yes, and it is the fastest, cheapest and most DIY-friendly way to support a deck: set the blocks on level, well-compacted gravel and the frame drops straight onto them, with no excavation and no concrete to mix. In a freeze climate the answer changes, because a block sits in the frost zone by definition and will be lifted by it. The colder the winters, the stronger the case for going below the frost line with buried sonotube piers, and in many northern jurisdictions that is not advice but a requirement. The middle option is a pre-cast pier cap with a built-in post anchor at $45 to $65, which is more stable than a bare block on a shallow pad without the cost of a full buried pier — a reasonable compromise in mild-frost regions.

A few inches, if the framing is shallow and the ground drains, but low decks trade one problem for another and the trade is worth understanding. What you gain is no guard requirement under 30 inches, no ledger, and often no permit. What you take on is moisture: framing close to damp ground rots faster, so keep every member off direct soil contact, leave airflow underneath rather than sealing the perimeter tight, and use ground-contact-rated pressure-treated lumber for anything near grade. Surface choice matters more here than on an elevated deck too. Composite is usually the smartest pick on a very low deck — it cannot rot, never needs staining, and re-coating wood is close to impossible once a deck sits a few inches off the ground and nobody can get underneath it.