The HVAC guy cut a 3-inch-wide notch across the double top plate of a 2x4 bearing wall for a duct.

Fix: Install a 3‑ply 1½"‑wide wood ledger (or a single 2x4) flush against the wall, spanning the full width of the notch, and secure it with (4) 16d common nails into each top plate, per IRC R502.5(1) and R602.6. This restores the load path and meets the inspector’s requirement.

Steps:

1. Cut a 2x4 to fit snugly across the notch.
2. Align it flush with the top of the double top plate.
3. Nail it in place using four 16d nails per connection (top plate to ledger).
4. Ensure the ledger extends at least 1½" beyond the notch on both sides.

This is a standard repair for notches in bearing walls. No structural engineer needed.

The inspector wants the double top plate continuity restored per IRC R602.3.2 (and IBC 2308.5.3). A 3″ notch severs the top plate’s ability to transfer shear and tie walls together.

Standard fix (prescriptive):

1. Install a 16-gauge (min) steel tie strap (e.g., Simpson LSTA24 or MSTA30) across the notch.
2. Fastener schedule: 12-16d (0.148″×3″) nails per side of the notch (24–32 total). Check the specific strap’s ICC-ES report; some require 16d sinkers (0.148″), others allow 10d (0.148″×1.5″) if the plate is single 2x.
3. Strap must span ≥24″ past each side of the notch (typically a 24″ or 30″ strap).

Critical details:

• Nails must penetrate full 1.5″ into the plate (don’t hit the duct).
• If the notch is >50% of plate width (1.75″ on a 2x4), the strap is mandatory—no exceptions.
• If the wall is a braced wall panel or shear wall, this notch likely kills its rating. You may need an engineered repair (steel side plates, epoxy bolts, or sister studs) and a letter from an SE.

Don't: Sister a 2x4 flat over the notch—it doesn’t restore tension capacity. Don't use drywall screws or fewer nails.

Bottom line: Strap it per the manufacturer’s ICC-ESR schedule, nail it heavy, call for re-inspection. If it’s a shear wall, hire an engineer before strapping.