Spot the Violation

FramingWalls & headersLevel 12018 IRC

Kitchen window rough opening

Inside face of a framed 2x6 exterior kitchen wall with OSB sheathing, before insulation. A window rough opening about 4 ft wide sits above a 2 in. PVC drain stub, red and blue PEX supply stubs and a blue electrical box whose yellow cable is stapled down the next stud. A built-up 2x12 header spans the top of the opening under the double top plate. On the left a king stud and a shorter stud beside it run down from the header to the bottom plate; on the right the header ends against a single full-height stud, with the opening running straight up that stud to the header. Ceiling joists sit on the top plate and a snowy yard shows through the opening. S-P-F No.2KD-HT 12 2" PVC DWV
Kitchen exterior wall at rough framing, window opening over the future sink

What's wrong here?

  1. The right end of the header has no jack stud or framing anchor carrying it
  2. A 4 ft opening in an exterior wall needs a triple 2x12 header
  3. The header must sit below the top plate with cripple studs between them
  4. Nothing. This installation is compliant
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Show the answer and the code reference

The answer

The right end of the window header has no jack stud under it; it hangs on nails driven through the king stud.

Correct choice: 1. The right end of the header has no jack stud or framing anchor carrying it

A header gathers the roof and ceiling load over the opening and delivers it to each end, so each end needs a bearing support. R602.7.5 requires headers to be supported on each end by one or more jack studs (trimmers), or by an approved framing anchor, as Table R602.7(1) lists for the span, and requires the full-height king stud beside each end to be end-nailed to the header. Here the left end sits on a jack but the right end is only end-nailed to the king, so the whole reaction is carried by four nails in shear. Over time the end drops, the window binds and the drywall cracks at the corner.

How to fix it

Cut a jack stud to fit tight under the right end of the header, sit it on the bottom plate and nail it to the king stud, then reframe the rough sill and opening width to suit. Where the opening cannot lose the 1-1/2 in. and the header table calls for a single jack, an approved framing anchor (header hanger) attached to the king and the header may be used instead.

Code references

  • IRC 2018 R602.7.5 — Supports for headers

    Headers must be supported on each end with one or more jack studs or with approved framing anchors in accordance with Table R602.7(1) or R602.7(2), and the full-height stud next to each end of the header must be end-nailed to it with four 16d nails.

    Drills citing R602.7.5

  • IRC 2018 R602.7 — Headers

    Headers in bearing walls are sized from Tables R602.7(1), R602.7(2) and R602.7(3); the tables also give the number of jack studs (NJ) required at each end for a given span.

    Drills citing R602.7

2024 IRC:not yet checked Confidence: low

Minnesota

MN adopts this rule as writtenConfidence: medium

Minnesota adopts the 2018 IRC with Minnesota amendments as the Minnesota Residential Code (Minn. Rules ch. 1309). No Minnesota amendment to R602.7.5 is known. DLI is adopting the 2024 IRC as the next edition; see the 2024 IRC note.

About the Minnesota Residential Code

Why the other choices are wrong

  • A 4 ft opening in an exterior wall needs a triple 2x12 header. For a 4 ft opening carrying only a roof and ceiling, a doubled 2x12 is well within the exterior bearing-wall spans of Table R602.7(1); the size is fine, the support at one end is not.
  • The header must sit below the top plate with cripple studs between them. Nothing in R602.7 requires cripples over a header; a header tight to the double top plate is standard practice and carries the load directly.
  • Nothing. This installation is compliant. R602.7.5 requires each end of a header to bear on one or more jack studs or an approved framing anchor; the right end is held only by end nails.
Code complianceLevel 1 · Apprentice#header#jack stud#trimmer#window#bearing wall

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