Spot the Violation

ElectricalRaceways & conduitLevel 32023 NEC

Laundry circuit across the basement

Unfinished basement looking at a poured concrete foundation wall, with the floor joists overhead shown end-on at 16 inches on center. A 1/2 in. EMT rises out of the top of a load center at the left, is strapped to the wall just above the panel, turns at the joists, and runs about 12 ft horizontally through holes bored in the middle of each joist with no straps along that stretch. At the right it turns down the wall, is strapped just above a 4 in. square box with a GFCI receptacle, and serves a washer and laundry tub.
Unfinished basement, laundry receptacle fed from the panel

What's wrong here?

  1. Nothing. This installation is compliant
  2. The horizontal EMT has no straps for more than 10 ft
  3. The bored joists need steel nail plates over the EMT
  4. EMT is not permitted through bored wood joists
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Show the answer and the code reference

The answer

Nothing is wrong: EMT run horizontally through bored joists is supported by the framing and only needs fastening within 3 ft of each termination.

Correct choice: 1. Nothing. This installation is compliant

358.30(A) normally requires EMT to be fastened every 10 ft and within 3 ft of each box or other termination. 358.30(B) adds that horizontal runs supported by openings through framing members at intervals not greater than 10 ft, and securely fastened within 3 ft of termination points, are permitted. Here the joists at 16 in. on center carry the tubing, and there are straps on the wall within 3 ft of the panel and of the receptacle box. The receptacle is a GFCI, as 210.8(A) requires for dwelling basements and laundry areas.

How to fix it

No correction needed. Keep the bored holes centered in the joist depth and within the framing limits of the residential building code.

Code references

  • NEC 2023 358.30(B) — Supports

    Horizontal runs of EMT supported by openings through framing members at intervals not greater than 3 m (10 ft) and securely fastened within 900 mm (3 ft) of termination points shall be permitted.

    Drills citing 358.30(B)

  • NEC 2023 358.30(A) — Securely Fastened

    EMT shall be securely fastened at least every 3 m (10 ft) and within 900 mm (3 ft) of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination.

    Drills citing 358.30(A)

  • NEC 2023 300.4(A)(1) — Bored Holes

    Holes bored in wood members for cable- or raceway-type wiring methods shall have their edge at least 32 mm (1-1/4 in.) from the nearest edge of the member, or the wiring shall be protected by a steel plate at least 1.6 mm (1/16 in.) thick. Exception No. 1: steel plates are not required to protect RMC, IMC, rigid nonmetallic conduit, or EMT.

    Drills citing 300.4(A)(1)

  • NEC 2023 210.8(A) — Dwelling Units

    GFCI protection is required for 125-250 V receptacles supplied by single-phase branch circuits rated 150 V or less to ground in the listed dwelling locations, which include basements and laundry areas.

    Drills citing 210.8(A)

2026 NEC:same rule and number. No 2026 change found to the 358.30(B) allowance for horizontal EMT runs carried through framing members at 10 ft or less and fastened within 3 ft of terminations. Based on absence of reported changes in 2026 summaries, not on the 2026 text. Confidence: medium

Minnesota

MN adopts the NEC rule as writtenConfidence: high

Minnesota adopted the 2023 NEC as the Minnesota Electrical Code effective July 1, 2023 (Minn. Stat. 326B.35; Minn. Rules 1315.0200) and adopts the NEC without section-by-section amendments. No Minnesota change to 358.30, 300.4, or 210.8(A) is known. Newer permits may fall under a later NEC edition; see the Minnesota page. Joist boring limits come from the Minnesota Residential Code (IRC-based), not the NEC. The Board of Electricity adopted the 2026 NEC, also without amendment, for permits filed on or after Aug. 17, 2026 (exams moved to the 2026 NEC on Sept. 8, 2026); see the 2026 NEC note on this drill.

How Minnesota adopts the NEC

Why the other choices are wrong

  • The horizontal EMT has no straps for more than 10 ft. 358.30(B) permits horizontal EMT runs supported by openings through framing members at intervals of 10 ft or less, provided the tubing is fastened within 3 ft of each termination, which it is at the panel and at the box.
  • The bored joists need steel nail plates over the EMT. The holes are centered in the joists, so the 1-1/4 in. setback is met anyway. Beyond that, 300.4(A)(1) Exception No. 1 says steel plates are not required for RMC, IMC, rigid nonmetallic conduit, or EMT, which resist nails and screws on their own.
  • EMT is not permitted through bored wood joists. 358.30(B) specifically recognizes horizontal EMT runs supported by openings through framing members; boring joists for raceway is a normal, permitted method, and these holes are centered where they least affect strength.
Code complianceLevel 3 · Master#emt#support#framing#basement#compliant

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