State of CT codes on drilling lumber.
State of CT codes on drilling lumber.
CHAPTER 3 - WIRING METHODS AND MATERIALS
(Add) 300.4.1 Drilling and notching.
(A) Structural floor, ceiling and roof members.
(1) Solid sawn lumber. Notches in solid lumber joists, rafters and beams shall not exceed one-
sixth of the depth of the member, shall not be longer than one-third of the depth of the member
and shall not be located in the middle one-third of the span. Notches at the ends of the member
shall not exceed one-fourth the depth of the member. The tension side of members 4 inches or
greater in nominal thickness shall not be notched except at the ends of the members. The
diameter of holes bored or cut into members shall not exceed one-third the depth of the
member. Holes shall not be closer than 2 inches to the top or bottom of the member, or to any
other hole located in the member. Where the member is also notched, the hole shall not be
closer than 2 inches to the notch.
Exception: Notches on cantilevered portions of rafters are permitted provided the
dimension of the remaining portion of the rafter is not less than 4-inch nominal and the
length of the cantilever does not exceed 24 inches.
(2) Engineered wood products. Cuts, notches and holes bored in trusses, laminated veneer
lumber, glue-laminated members or l-joists are not permitted unless the effects of such
penetrations are specifically considered in the design of the member and permitted by the
manufacturer.
(B) Studs. Any stud in an exterior wall or interior bearing partition may be cut or notched to a
depth not exceeding 25 per cent of its width. Studs in nonbearing interior partitions may be
notched to a depth not to exceed 40 per cent of a single stud width. Any stud may be bored or
drilled, provided that the diameter of the resulting hole is no greater than 40 per cent of the stud
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width, the edge of the hole is no closer than 5/8 inch to the edge of the stud and the hole is not
located in the same section as a cut or notch.
Exceptions:
1. A stud may be bored or drilled to a diameter not exceeding 60 per cent of its width,
provided that such studs located in exterior walls or interior bearing partitions are
doubled and not more than two successive studs are bored.
2. Approved stud shoes may be used when installed in accordance with the
manufacturer's recommendations.
(C) Top plates. When wiring or conduit is placed in or partly in an exterior wall or interior
bearing partition necessitating cutting, drilling or notching of the top plate by more than 50 per
cent of its width, a galvanized metal tie of not less than 0.054 inches thick (16 ga) and 1 %
inches wide shall be fastened to each plate across and to each side of the opening with not less
than eight 16d nails at each side or equivalent.
Exception: When the entire side of the wall with the notch is covered by wood structural
panel sheathing.
