Multiple Small-Diameter Holes for Electrical Cables

Drilling multiple small-diameter holes through engineered wood structural members to route electrical cables is a common practice, but it carries structural risks. When done incorrectly, this practice can compromise the load-bearing capacity of wood I-joists, structural composite lumber (SCL), and glued laminated timber (glulam), creating safety concerns.

This publication is designed for: engineers, builders, contractors

This publication provides guidance, based on electrical and building code provisions, on how to properly cut holes and install electrical cables in engineered wood products. It addresses the relationship between electrical code compliance and structural integrity, offering recommendations that align with both the National Electrical Code (NEC) and the International Residential Code (IRC) while protecting the structural performance of engineered wood members. It includes detailed photographs of wiring in residential construction and references to key sections of the NEC and IRC.

Published by APA — The Engineered Wood Association.