Joist Hanger Screws vs Nails: What the Code Actually Requires

Most DIYers get this wrong: you cannot use standard screws or drywall screws in joist hangers. The IRC building code is specific about fastener type for structural connectors. Here is exactly what is required.

The Code Requirement

IRC Section R802.3 and IBC Section 2304.9 require that structural connector fasteners be installed per the manufacturer's ICC-ES evaluation report (ESR). For Simpson Strong-Tie hangers, that means:

• 10d common nails (0.148" diameter x 1-1/2" long) for most standard hangers
• Simpson Strong-Drive SD connector screws (1-1/2" or 3") where screws are specified
• Never drywall screws, deck screws, or standard wood screws

Why Regular Screws Fail in Hangers

Joist hangers are loaded primarily in shear — the fastener resists the joist being pulled downward. Screws resist tension (pulling out) well but have poor shear strength compared to nails of the same diameter. A drywall screw in a joist hanger can snap under shear load at a fraction of the rated capacity. This is why the code specifically requires the fastener type listed in the ESR report.

Hanger Nail vs Hanger Screw Comparison

Hanger Nail Sizes Quick Reference

• 1-1/2" x 0.148" (10d Short): Standard for most face-mount hangers — LUS, LUS-SDS, HUS series
• 3" x 0.131" (16d Sinker): For top-flange connections and heavy hangers
• 1-1/2" x 0.131": For lighter hangers and sloped connectors
• Joist hanger nails (short): Pre-packaged specifically for hanger holes — do not substitute

Can I Use Screws Instead of Nails in Joist Hangers?

Yes — but only Simpson Strong-Drive SD screws or equivalent connector screws listed in the hanger ESR report. The ESR report for each Simpson product lists approved fasteners and the load values you get with each. Using SD screws typically gives the same or higher load values than 10d nails and is preferred where a nail gun is not available.

Never substitute standard wood screws, deck screws, or drywall screws regardless of length or gauge. These are not rated for shear in structural connectors and will fail under load.

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Frequently Asked Questions

Can I use screws instead of nails in joist hangers?

Yes but only specific connector screws listed in the hanger manufacturer ESR report - typically Simpson Strong-Drive SD screws. Standard deck screws, drywall screws, and wood screws are NOT code compliant in joist hangers. They lack the shear strength rating required for structural connectors. Using non-rated fasteners voids the load rating of the hanger.

Why can I not use drywall screws in joist hangers?

Drywall screws are hardened and brittle to drive through gypsum cleanly. They have poor shear strength and snap under lateral load. Joist hangers are loaded primarily in shear - the fastener resists the joist being pulled downward. A drywall screw in a joist hanger can fail at a fraction of the rated capacity under normal floor loads.

What nails do I use for Simpson Strong-Tie joist hangers?

Most Simpson face-mount hangers require 10d common nails (0.148 inch diameter x 1-1/2 inch long). The specific nail size is listed in the product installation instructions and the ICC-ES ESR report for each hanger model. Never substitute a different nail size or type - the load rating is calculated for the specified fastener.

Are Simpson SD screws better than nails for joist hangers?

Simpson SD screws typically provide equal or higher load values than 10d nails in the same hanger and are preferred where a nail gun is not available. They are also easier to install in tight spaces and easier to remove if adjustment is needed. Use the 1-1/2 inch SD screw where 10d nails are specified.

What happens if I use the wrong fasteners in joist hangers?

Using non-rated fasteners in joist hangers voids the engineered load rating of the connector. The connection may appear sound visually but carry significantly less load than rated. This is a structural deficiency that building inspectors will flag and that can lead to floor failure under normal occupancy loads. Always use manufacturer-specified fasteners.

Related Guides

• Joist Hangers vs Toenailing — When to use each
• Structural Screws vs Lag Bolts — For framing connections
• Deck Ledger Attachment — How to anchor your ledger board
• AI Foreman — Complete project planning for deck and framing work
• Nail Size Chart: Penny Sizing Explained — Common vs sinker vs box nail diameters, and the real IRC requirements