Spot the Violation

FramingFloor framingLevel 12018 IRC

Framed opening under a bathroom

Looking up at a basement ceiling under a bathroom, where one floor joist has been cut and headered off around a toilet drain. A doubled 2x10 header spans the opening; at its right end it sits in a galvanized double-width face-mount hanger on the doubled trimmer, with a bright round nail head in every hole. A single short tail joist runs toward the camera and sits in a galvanized face-mount hanger near the middle of the header; that hanger's face flanges hold black bugle-head screws with Phillips recesses, two of its face holes are open, and the small holes in its side flange are open. A white 3-inch PVC drain drops through the opening and runs away below the joists. S-P-FNo.2 KD-HT
Basement ceiling under a bathroom, toilet drain opening

What's wrong here?

  1. The tail joist hanger is fastened with drywall screws, with open face and joist nail holes
  2. A header this short must be a single joist, so doubling it is not allowed
  3. The header-to-trimmer hangers are not allowed because hangers are only required when the header span exceeds 6 ft
  4. Nothing. This installation is compliant
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Show the answer and the code reference

The answer

The hanger carrying the tail joist is fastened to the header with black drywall screws instead of the specified hanger nails, and some face holes and all of the joist-side holes are empty.

Correct choice: 1. The tail joist hanger is fastened with drywall screws, with open face and joist nail holes

R502.6 lets a joist end be carried by approved joist hangers instead of bearing on a support. Approved means acceptable to the building official (R202), and a hanger is accepted on the strength of its manufacturer's tested load ratings, which assume the specified nails (or the maker's own listed connector screws) in every specified hole. Drywall screws are thin and hardened, so they snap in shear instead of bending the way a nail does, and hanger manufacturers do not allow them as a substitute. With two face holes and all of the joist-side holes empty, the tail joist and the toilet above it are hanging on a few brittle screws. The trimmer hanger at the end of the header shows the correct installation: a nail in every hole.

How to fix it

Remove the screws and fill every face and joist hole with the nails the hanger manufacturer specifies (typically 10d or 16d commons in the face and the listed joist nails in the side flanges), or with the manufacturer's listed structural connector screws. Replace the hanger if the screws have enlarged or torn its holes.

Code references

  • IRC 2018 R502.6 — Bearing

    The ends of each joist, beam or girder must have at least 1-1/2 in. of bearing on wood or metal or at least 3 in. on masonry or concrete, or be supported by approved joist hangers.

    Drills citing R502.6

  • IRC 2018 R502.10 — Framing of openings

    Openings in floor framing are framed with header and trimmer joists. Headers spanning more than 4 ft and their trimmers must be doubled, approved hangers are required for header-to-trimmer connections when the header spans more than 6 ft, and tail joists over 12 ft long must be supported on framing anchors or 2x2 ledger strips.

    Drills citing R502.10

  • Other Hanger manufacturer's installation instructions — Connector fasteners

    Hanger manufacturers' catalogs and installation guides (for example Simpson Strong-Tie's) give the nail size and count for every hole and do not allow ordinary wood, deck or drywall screws in place of the specified nails; only the manufacturer's own listed connector screws may substitute.

    Drills citing Hanger manufacturer's installation instructions

2024 IRC:same rule and number. Summaries of the 2024 IRC give the same R502.6 bearing text: 1-1/2 in. on wood or metal, 3 in. on masonry or concrete, or approved joist hangers. Not checked line by line against the printed 2024 IRC. Confidence: medium

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 R502.6 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 header this short must be a single joist, so doubling it is not allowed. R502.10 requires doubling only when the header span exceeds 4 ft; it never prohibits a doubled header, which simply has extra capacity.
  • The header-to-trimmer hangers are not allowed because hangers are only required when the header span exceeds 6 ft. The 6 ft trigger in R502.10 is when hangers become mandatory; using approved hangers on a shorter header is always acceptable and is better than end-nailing.
  • Nothing. This installation is compliant. A joist hanger is only an approved support (R502.6) when it is fastened as its manufacturer specifies, and drywall screws with empty holes do not meet that.
Safety hazardLevel 1 · Apprentice#joist hanger#fasteners#drywall screws#header#basement#bathroom

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