Do I need joist hangers on all joists?

Joist hangers are required wherever joists frame into the side of a beam or header rather than resting on top of a bearing surface. For joists sitting on top of a sill plate, beam, or ledger, hangers are optional but recommended in seismic and high-wind zones for uplift resistance.

What nails do I use for joist hangers?

Use 1.5-inch x 10-gauge joist hanger nails (Simpson part number N10A). Do not use regular 16d sinkers — they are too long and too thin for the punched nail holes. Using the wrong nails dramatically reduces the hanger's rated load capacity. Some hangers also require specific screws in certain holes — check the installation instructions.

Can I use screws instead of nails in joist hangers?

Only if the screws are specifically rated for structural connector use, such as Simpson Strong-Drive SD screws. Regular drywall screws or deck screws are not allowed because they are too brittle for shear loads. The Simpson SD9112 is the most common structural screw approved for joist hanger use.

What size joist hanger do I need?

The hanger must match the exact joist dimensions. A 2x10 joist requires an LUS210 hanger. Using the wrong size hanger means the joist does not bear properly, which reduces load capacity and is a code violation. For doubled or tripled joists, use the corresponding double or triple hanger model.

How much do joist hangers cost?

Standard Simpson LUS-series joist hangers cost $1.50 to $5.00 each depending on size. A 30-joist floor system with hangers at both ends costs $90 to $300 in hangers alone. Budget an additional $20 to $40 for 10-pound boxes of joist hanger nails. Specialty hangers for I-joists or skewed connections can cost $8 to $15 each.

Joist Hanger Calculator

How many joist hangers do I need? Free calculator for standard joist hanger connectors — covers floor and ceiling joist framing.

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Enter Your Measurements

How to Use This Calculator

1Enter the total number of joists or rafters that need hangers.
2Click Calculate.

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About This Material

Joist hangers are galvanized steel connectors that support the ends of floor joists, ceiling joists, or rafters where they frame into a beam, header, or ledger board. The most common residential models are the Simpson Strong-Tie LUS series (for dimensional lumber) and the LB series (light-capacity applications). Hangers are sized to match the exact joist dimensions — LUS26 for 2x6, LUS28 for 2x8, LUS210 for 2x10, and LUS212 for 2x12. For engineered I-joists, use the manufacturer-specified hanger (like the IUS series). Each hanger has a rated load capacity that assumes all nail holes are filled with the correct joist hanger nails (1.5-inch x 10-gauge short stocky nails, not regular 16d nails). Individual hangers cost $1.50 to $5.00 each depending on size. Joist hanger nails are sold separately in 1-pound and 10-pound boxes. For specialty connections like skewed joists, sloped rafters, or double joists, Simpson offers adjustable and heavy-duty hanger models.

Next Steps:

Floor Joist Calculator →Framing Nail Calculator →

Installation Tips

•Use all the nail holes — every nail matters for rated load capacity.
•Use joist hanger nails (1.5" x 10d) — do NOT use regular 16d nails.
•Check the hanger is specified for your joist size.

Common Mistakes to Avoid

Under-nailing hangers — partial nailing dramatically reduces capacity.
Using the wrong size hanger for the joist.
Using plain-shank nails instead of specified joist hanger nails.

Joist Hanger Calculator

How to Use This Calculator

About This Material

Installation Tips

Common Mistakes to Avoid

Frequently Asked Questions

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