Select the right joist hanger based on joist size, load requirements, and installation angle. Reference guide for residential framing.
Joist hangers are metal connectors that provide a code-approved method for attaching floor joists, ceiling joists, and deck joists to beams and headers without relying solely on toenails. Selecting the correct hanger ensures the connection can carry the designed loads safely.
This joist hanger selection calculator helps you choose the right hanger model based on your joist size, the load it must carry, and whether the connection is square or at an angle. It references common residential hanger types similar to Simpson Strong-Tie's LUS and LU series.
Proper hanger selection is critical for structural integrity, especially at openings in the floor where headers carry multiple joist loads, and on decks where connections are subject to inspection. Using the wrong hanger or underloading a connection can lead to floor sag, squeaks, or worse.
This data-driven approach helps contractors minimize rework, avoid delays caused by material shortages, and deliver projects on time and within the agreed budget.
Building codes require engineered connections for joist-to-beam attachments. This calculator quickly identifies the correct hanger size and confirms its load capacity meets your design requirements, saving time flipping through manufacturer catalogs. Regular use of this calculation supports compliance with building codes and inspection requirements, helping projects proceed smoothly through the permitting and approval process.
Required load capacity ≥ (tributary width / 2) × joist span × total load (psf) Select hanger where: Allowable download ≥ Required load Hanger size must match joist dimensions exactly
Result: LUS210 (1,185 lb capacity)
A 2×10 joist carrying 800 lbs fits a standard LUS210 face-mount hanger with an allowable download of 1,185 lbs. The hanger accepts 2×10 nominal dimensions and mounts to the face of the beam or header.
The most common residential joist hangers are the LUS (face-mount) and?"LU series. LUS26, LUS28, LUS210, and LUS212 handle 2×6 through 2×12 joists respectively. Double-joist hangers (LUS2-series) are available for doubled trimmers at openings.
Seat the joist fully in the hanger before nailing. Fill every hole with the specified nail—empty holes reduce the rated capacity proportionally. Bend the tabs tight against the joist and ensure the hanger flanges are flush against the beam face with no gaps.
For point loads exceeding standard hanger capacity, multi-ply beams, steel beams, or unusual angles, consult a structural engineer. They may specify a custom welded bracket, a concealed hanger, or a bolted connection that can't be selected from a standard catalog.
Toenailing is code-approved for some connections, but joist hangers provide significantly more capacity and consistency. Most building departments require hangers for floor joist-to-beam connections and all deck connections.
Use 1-1/2″ x .148″ joist hanger nails (also called 10d x 1-1/2″ short). Never use standard 16d sinkers, framing nails, or drywall screws—they don't fit the holes and lack the shear capacity.
Hangers are required wherever a joist bears on a beam or header without resting on top. If the joist sits on top of a beam, hangers aren't needed at that end, though hurricane ties may be required.
LUS hangers have a sloped seat for top-flange mounting and are used where the joist attaches at the same height as the beam top. LU hangers are face-mount types where the joist hangs below the beam top.
Standard galvanized (G90) hangers work with most ACQ and CA-treated lumber. For saltwater exposure or ground contact, use stainless steel or ZMAX-coated hangers as recommended by the connector manufacturer.
Multiply the tributary width (half the spacing to each side) by the joist span and the total load per square foot (typically 50 psf for residential floors: 40 live + 10 dead). For example, a joist at 16″ OC spanning 12 feet carries (1.33 ft)(12 ft)(50 psf) = 800 lbs per end.