Wash. Admin. Code § 296-150C-1000 - Drilling or notching of wood wall structural members

(1) Cutting and notching. In exterior walls and bearing partitions, any wood stud may be cut or notched to a depth not exceeding twenty-five percent of its width. Cutting or notching of studs to a depth not greater than forty percent of the width of the stud is permitted in nonbearing partitions supporting no loads other than the weight of the partition.
(2) Bored holes. A hole not greater in diameter than forty percent of the stud width may be bored in any wood stud. Bored holes not greater than sixty percent of the width of the stud are permitted in nonbearing partitions or in any wall where each bored stud is doubled, provided not more than two such successive doubled studs are so bored.

In no case shall the edge of the bored hole be nearer than 5/8 inch (16mm) to the edge of the stud. Bored holes shall not be located at the same section of stud as a cut or notch.

(3) Drilling or notching of studs greater than allowed in subsection (1) or (2) of this section must be substantiated by engineering analysis.


Wash. Admin. Code § 296-150C-1000

Statutory Authority: RCW 43.22.340, [43.22.]355,[43.22.]360 , [43.22.]432, [43.22.]440 and [43.22.]480. 96-21-146, § 296-150C-1000, filed 10/23/96, effective 11/25/96.

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