Joist Hangers for Stairs: How Many You Need and Why

Every stringer that hangs off a rim joist or header — rather than bearing directly on a post or footing — needs its own hanger, and every landing joist framed between two headers needs a hanger at each end. For a typical deck stair with 2 stringers hung off the rim joist and a landing framed with 4 joists between double headers, that’s 2 stringer hangers plus 8 joist hangers — 10 total, not counting any hangers needed where the landing itself connects back to the main deck frame. Run your own configuration through the Joist Hanger Count Calculator to get an exact count before you order hardware.

How to count joist hangers for a stair

Start by identifying every connection where a framing member’s end is supported by hanging off another member instead of resting on top of a post, beam, or footing. Stair stringers hung from a header need a hanger specifically rated for the sloped connection — IRC R507.13.2 requires a minimum capacity of 625 lb / 2,835 N for these — one per stringer. A landing framed independently, with joists spanning between two header beams, needs a hanger at both ends of every joist, since neither end simply rests on top of anything.

Worked example: a stair 42 in / 1,067 mm wide is built with 3 stringers (outer two plus a center stringer for the extra width), all hung from a header with stair-rated hangers — that’s 3 hangers. The landing at the base is framed with 4 joists spanning between a pair of double 2×10 headers, hung at both ends — that’s 4 joists x 2 ends = 8 hangers. Total for this configuration: 11 joist hangers, before accounting for any hanger needed where that landing header ties back into the main deck or house framing.

Hanger counts by stair configuration

These figures assume a straight-run stair with stringers hung from a header at the top, and an independently framed landing at the bottom with joists hung at both ends. Actual counts shift with landing size and whether the landing bears on posts instead of hanging from headers.

Stair width	Stringers (hung)	Landing joists	Total hangers
36 in / 914 mm	2	3	8
42 in / 1,067 mm	3	4	11
48 in / 1,219 mm	3	5	13
60 in / 1,524 mm	4	6	16

Common mistakes

Using standard face-mount joist hangers instead of stair-rated hangers. A generic 2x hanger built for a level, square joist connection doesn’t seat correctly on an angled stringer and isn’t rated for the sloped connection load IRC R507.13.2 requires. Fix: buy hangers specifically designed and load-rated for stringer-to-header connections, not repurposed floor-joist hardware.

Leaving hanger nail holes partially empty. A hanger’s published load rating assumes every specified hole is filled with the correct fastener type and length. Skipping half the holes to save a few minutes doesn’t cut the capacity in half evenly — it can drop it well below what the connection actually needs to carry, since the remaining fasteners take a disproportionate share of the load. Fix: fill every hole with the manufacturer-specified nail or structural screw, no exceptions.

Mixing incompatible hanger and fastener coatings. Installing a hot-dip galvanized (HDG) or ZMAX hanger with plain, uncoated nails — or the reverse — sets up galvanic corrosion, especially in ACQ-treated lumber, which is common in deck and stair construction. The connection can look fine for a couple of years while corroding from the inside. Fix: match hanger coating to fastener coating — HDG or ZMAX hangers with hot-dip galvanized nails (ASTM A153), stainless hangers with stainless fasteners.

Skipping hangers on interior landing joists because the ends ‘look supported.’ On a landing with more than two joists, it’s easy to hang the outer two carefully and let the interior joists rest on a ledger strip or get a couple of toe-nails instead of a proper hanger. Those joists sag under load over time, which shows up as a soft spot or slight slope across the landing. Fix: hang every joist-to-header connection shown on the framing plan, interior joists included.

Related calculators you might need

Before counting hangers, confirm the ledger or header they attach to is fastened correctly — the Ledger Board Attachment Calculator checks that connection. If you haven’t settled on stringer count yet, the Stringer Spacing Calculator determines how many stringers a given stair width needs. For the landing framing itself, run dimensions through the Landing Framing Calculator, and check the header spanning to the stringers with the Stair Beam Span Calculator. If the whole assembly is part of a deck, the Deck Stair Calculator ties the geometry together.

Frequently asked questions

How many joist hangers do I need for deck stairs?

It depends on stringer count and landing size, but a typical 36 in wide stair with 2 hung stringers and a 3-joist landing needs around 8 hangers total. Wider stairs with a center stringer and larger landings need more — run your specific dimensions through the Joist Hanger Count Calculator for an exact number.

Do stair stringers need special joist hangers?

Yes. IRC R507.13.2 requires hangers specifically designed for sloped stringer connections, rated for a minimum capacity of 625 lb. A standard flat joist hanger isn’t shaped for the stringer angle and isn’t rated for this connection.

What size nails go in a stair stringer hanger?

Use the exact nail or structural screw type and length specified by the hanger manufacturer for that hanger model — hanger load ratings are tested with a specific fastener, and substituting a different nail size or type invalidates the published capacity.

Can I toe-nail a landing joist instead of using a hanger?

Toe-nailing alone doesn’t meet code for a joist framed between two headers where the joist end isn’t bearing on top of anything — it needs a rated hanger at each end. Toe-nailing is only appropriate for specific blocking conditions the code calls out separately, not as a substitute for a hanger.

Why do my stringer hangers need a 625 lb rating?

IRC R507.13.2 sets that minimum specifically for hangers supporting sloped stringer connections, since the angled load path puts different stress on the hanger than a standard level joist connection. A lower-rated or standard hanger doesn’t meet this requirement even if it physically fits.