Deck Footings & Frost Depth in Central Ohio

It's the part of a deck nobody sees and everybody's deck depends on: the footings. In Central Ohio, getting them right isn't optional — our freeze-thaw winters punish any deck built on footings that stop too shallow. Here's what actually goes on underground, why depth matters so much here, and how the options compare.

The short answer: below the frost line

Deck footings in Central Ohio have to reach below the frost line — the depth to which the ground reliably freezes in winter. Local codes here generally put that around 30 to 32 inches, though the exact minimum is set by your building department (the Delaware County office and each village or township can specify it) and is confirmed when you pull the permit. A footing poured to that depth sits in soil that stays unfrozen all winter, so it doesn't move.

Why frost depth is the whole game

When wet soil freezes it expands and lifts — that's frost heave. Central Ohio doesn't freeze once and stay frozen; it crosses the freezing point dozens of times each winter. A footing that ends above the frost line gets shoved up and dropped back down over and over. Multiply that across a season and the result is a deck that's out of level, a ledger board straining against the house, railings that rack, and gaps that open at the connections. A footing anchored below the frost line simply doesn't ride that cycle. This is the same reason a paver patio outlasts a concrete slab here — freeze-thaw is the deciding force for anything built on Ohio ground.

Your three footing options

• Poured concrete piers — the standard for permanent decks here. A hole is augered below the frost line and filled with concrete, often with a wider base and a post anchor set on top. Proven, strong, and what most inspectors expect to see.
• Helical (screw) piles — steel piles driven down to load-bearing depth. Great for tricky soil, tight access, or when you want no concrete cure time; typically costs more than poured piers.
• Precast deck blocks — surface blocks that sit above the frost line. They heave in Ohio winters, so they're only appropriate for a temporary or floating ground-level platform — not a permanent attached deck, and generally not approvable for one.

Depth isn't the only spec

How wide a footing needs to be depends on what it carries — the deck's size, height, and the soil's bearing capacity. A tall or large deck concentrates more load on each post, so footings get bigger. This is exactly the kind of thing the permit and inspection process checks, which is one more reason a deck should be permitted properly rather than built on guesswork.

The inspection step

On a permitted deck, the building department inspects the footings before any framing goes up — confirming depth and diameter while the holes are still open. We dig to code depth, call for that inspection, and don't build over it until it passes. It adds a day to the schedule and it's worth every hour: it's the one part of the deck you can never check again once it's covered.

That's the same footing spec on every deck we build — whether it's a new deck in Lewis Center, a composite deck replacement in Powell, or a walkout deck in Galena. The frost line doesn't care which township you're in.