Code Q&A: Protection of Raceways and Cables in Wood Framing Members

Aug. 11, 2022

Test your knowledge of the NEC.

Based on the 2020 NEC.

Q. What are the Code rules relating to the protection of raceways and cables through wood members?

See answer below.

A. Holes through wood framing members for cables or raceways must be not less than 1¼ in. from the edge of the wood member. If the edge of a drilled hole in a wood framing member is less than 1¼ in. from the edge, a 1⁄16 in. thick steel plate of enough length and width must be installed to protect the wiring method from screws and nails [Sec. 300.4(A)(1)] (Figure).

wiring methods protection against physical damage bored holes in wood members

Exception No. 1: A steel plate is not required to protect rigid metal conduit, intermediate metal conduit, PVC conduit, or electrical metallic tubing.

If notching of wood framing members for cables and raceways is permitted by the building code, a 1⁄16 in. thick steel plate of enough length and width must be installed to protect the wiring method laid in those wood notches from screws and nails [Sec. 300.3(A)(2)].

CAUTION: Many wood and metal framing members (especially joists and beams) have specific drilling and/or notching instructions meant to maintain structural integrity. Be sure to check with the building official for building code requirements.

These materials are provided to us by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code.

About the Author

Mike Holt

Mike Holt is the owner of Mike Holt Enterprises (www.MikeHolt.com), one of the largest electrical publishers in the United States. He earned a master's degree in the Business Administration Program (MBA) from the University of Miami. He earned his reputation as a National Electrical Code (NEC) expert by working his way up through the electrical trade. Formally a construction editor for two different trade publications, Mike started his career as an apprentice electrician and eventually became a master electrician, an electrical inspector, a contractor, and an educator. Mike has taught more than 1,000 classes on 30 different electrical-related subjects — ranging from alarm installations to exam preparation and voltage drop calculations. He continues to produce seminars, videos, books, and online training for the trade as well as contribute monthly Code content to EC&M magazine.