Good deck framing is why some decks are still standing after 20 years while others sag within five.
Before the first deck board goes down, there’s a skeleton of posts, beams, joists, and hardware holding everything together.
Get the framing right, and the rest of the deck almost takes care of itself. Get it wrong, and no amount of sturdy composite decking will save you.
Here’s what you need to know about how it all fits together and how to lay it out correctly.
The Core Components of Deck Framing
Deck framing isn’t one thing. It’s a chain of structural members, each playing a specific role.
When one is undersized or improperly installed, the whole chain weakens.
Before starting any deck-building project, you need a clear mental picture of what those parts are and how they connect.
A quick overview of the full system:
| Component | Role |
| Footings | Anchor the deck to the ground below the frost line |
| Deck Posts | Transfer weight from the frame down to the footings |
| Beams | Carry the load of the joists across the span |
| Joists | Support the deck boards and distribute weight to the beams |
| Ledger Board | Attaches the deck frame to the house (on attached decks) |
| Rim Joists | Cap the perimeter of the frame and hold joists in place |
| Joist Hangers | Metal connectors that keep joists tied securely to beams |
Let’s walk through each one.
Footings and Concrete
Footings are the foundation, and they determine whether your deck stays solid or starts to shift over time.
They need to be poured below the frost line, because when ground freezes and thaws through Indiana winters, any footing above that depth will heave and throw off your entire frame.
The depth you need depends on your local code, but in central Indiana, footings typically need to reach at least 36 inches below grade. That said, always confirm the exact requirement with your local building department before you dig.
The hole gets dug with a power auger or hand digger, concrete forms are set, and then poured concrete fills the void. Once it cures, a post anchor is set into the top. That post anchor is what keeps the base of your posts from rotting out over time.
Posts
The deck posts are the vertical members rising from the footings up to support the beam above. Their size depends on the height of the deck and the load they’re carrying. For instance, taller and heavier decks often require 6×6 posts rather than 4x4s.
Posts need to be perfectly plumb. One that’s even slightly off plumb makes squaring the rest of the frame harder.
Pressure-treated lumber is the default for deck posts because it resists the rot and moisture that would eat through standard dimensional lumber in a few seasons.
You can also go with steel or aluminum posts in certain builds, which brings serious corrosion resistance, especially relevant in environments prone to high winds or salt air.
Beams
Beams run horizontally across the top of the posts and carry the weight of all the joists above them.
Think of them as the spine of the deck frame. The lumber size you need for your beams depends on how far they span between post locations and the total load the deck is designed to handle.
One thing worth knowing: the International Residential Code updated beam sizing tables and made it explicitly clear that you need to spec your decking material before you frame.
If you plan on laying composite decking that requires 12-inch joist spacing, and your beam span calculation assumed 16-inch spacing, you’ve got a code problem.
Joists
The joists form the grid that everything else rests on. They run perpendicular to the beams, spaced typically at 12 or 16 inches on center, and they’re what the deck boards attach to.
Their size and spacing determine how much flex you feel underfoot, and whether your deck boards stay flat over years of use.
Joist tape, applied to the top face of each joist before the deck boards go down, is a small detail that pays for itself over the life of the deck.
Wood is porous, and standing water at the joist-to-board connection is one of the fastest ways to accelerate rot, even in pressure-treated lumber. The joist tape creates a barrier that keeps moisture from settling in.
Joist hangers are the metal connectors at each end of the joist that attach it to the rim joist or ledger. The right hanger, properly nailed with the specified fasteners, keeps each joist tight and prevents the kind of lateral movement that eventually leads to squeaky, bouncy deck boards.
Ledger Board
On attached decks, the ledger board is the piece of lumber bolted to the house that the deck frame connects to on one side.
It’s one of the most critical connections in the entire build, and also one of the most commonly failed inspection points.
The ledger must be properly flashed so water can’t get behind it and into your home’s rim joist or sheathing.
Flashing that’s cut short, improperly overlapped, or sealed with caulk alone instead of metal flashing is how decks end up causing thousands of dollars in water damage.
How To Lay Out the Deck Frame, Step-By-Step
With a solid understanding of each component, laying out the deck frame becomes a methodical process:
- Measure out from the house to establish your perimeter. Pull a string line out from your ledger at each corner to define the outer edges of the deck.
- Check your corners for square using the 3-4-5 triangle method. Run a tape measure diagonally across the layout and adjust until both diagonal measurements match. On larger decks, a laser level speeds this up and keeps small errors from compounding across a long span.
- Mark your post locations on the ground. Most residential decks keep structural posts no more than 8 feet apart on center, though that depends on beam size and load. Mark the center of each footing hole clearly before you dig.
- Dig your footing holes and pour concrete. Set the concrete forms, fill with poured concrete, and let it cure fully before moving on.
- Set your post anchors into the cured concrete. These keep your posts elevated slightly off the concrete surface, which is what prevents moisture from wicking up into the base of each post over time.
- Install posts plumb and set beams on top. Check plumb on every post before securing. The beams go on top of or alongside the posts, fastened with metal post caps.
- Install rim joists to define the outer frame. These cap the perimeter and give you the boundary the interior joists will connect to.
- Mark joist layout on the rim joists before installing. Do this while the rim boards are accessible so your spacing marks are accurate and consistent across the full span. Account for railing post locations here too, since through-bolted railing posts can conflict with joist placement.
- Install interior joists with joist hangers on both ends. Work at your specified spacing, 16 inches on center for most straight composite layouts, 12 inches for diagonal. Double up joists anywhere a heavy point load like a hot tub or planter will sit.
FAQ: Deck Framing Method
How deep do deck footings need to be in Indiana?
In central Indiana, footings typically need to reach at least 36 inches below grade to get below the frost line. That said, your local building department sets the exact requirement for your address. Always confirm before you dig.
What’s the difference between beams and joists in deck construction?
Beams are the primary horizontal supports that span between the deck posts. Joists run perpendicular to the beams and carry the deck boards. Beams handle the main load transfer down to the posts and footings; joists distribute weight from the surface across to the beams.
Do I need joist hangers for every joist?
Yes, for any joist that terminates into a rim joist or ledger, metal joist hangers are required by code. They provide a reliable, tested connection that toe-nailing simply can’t match for lateral strength.
What is joist tape and do I actually need it?
Joist tape is a self-adhesive waterproof tape applied to the top of each joist before deck boards are attached. It protects the joist from moisture that collects at the board-to-joist interface. It’s a low-cost addition that significantly extends joist life, especially in climates with freeze-thaw cycles like Indiana’s.
Is steel or aluminum framing worth it for a residential deck?
Pressure-treated is widely available, cost-effective, and it handles moisture well. Steel deck framing has grown in use for commercial applications and high-wind zones, and aluminum shows up in coastal builds where salt air accelerates corrosion in standard metal hardware. For Indiana homeowners, pressure-treated lumber paired with quality composite decking on top is the combination that still makes the most sense.
Honestly, You Could Just Let Us Handle It
Knowing how deck framing works helps you ask better questions and make smarter decisions about your build.
But between the footing depths, beam sizing tables, joist spacing requirements, code compliance, ledger flashing details, and layout geometry, there’s a lot that can quietly go sideways on a project if you’re doing it for the first time.
At Decks on Point, deck building is what we do every day. We’ve completed 300+ projects across Westfield, Noblesville, Carmel, McCordsville, and the wider Indiana area, and every build comes with a lifetime warranty.
You get a properly framed, properly flashed, code-compliant deck built with materials that’ll actually last.
Ready to talk through your project? Call us at (317) 903-2431 or message us here.