STEEL FRAMING
200-105
02/09
© NORTHWEST WALL AND CEILING BUREAU
Notching, cutting or boring holes in non-structural light gauge metal framing members for the installation of MEP elements must take into consideration the effects to the structural integrity of the framing member.
The Steel Stud Manufacturers Association (SSMA) ICBO ER-4943P is very specific as to the allowable size and location of punch-outs.
General Note #4 states:
“When provided, factory punch-outs will be located along the centerline of the webs of the members and will have a minimum center-to-center spacing of 24.” Punch-outs will have a maximum width = half the member depth
(d/2) or 2-1/2,” whichever is less, and a maximum length
= 4-1/2.” The minimum distance between the end of the member and the near edge of the web punch-out = 10.”
Engineering calculations performed by the SSMA have determined that punch-outs meeting these criteria will not compromise the integrity ofthe stud.”
The International Plumbing and Fuel Gas Codes are also very precise about modifying light gauge framing members. Although the section reference may bary per disciplpine, the standards are by and large addressed in Section 302 “Protection of Structure” or “Structural
Safety,” are consistent in how to address modifications to light gauge framing members and states the following:
“Cutting, notching and boring holes in nonstructural cold-formed steel wall framing. Flanges and lips of nonstructural cold-formed steel wall studs shall not be cut or notched. Holes in webs of nonstructural cold-formed steel wall studs shall be permitted along the center-line of the web of the framing member, shall not exceed 1.5 inches (38mm) in width or 4 inches (102mm) in length, and shall not be spaced less than 24 inches (610 mm) center to center from another hole or less than 10 inches
(254 mm) from the bearing end.”
If punch-outs are provided in a stud member, no other punch-outs or holes are allowed unless they are within the criteria established by the SSMA. The stud flanges and lips of stud members shall not be cut or notched. If additional holes are bored or flanges and lips notched or cut, the integrity of the member cannot be guaranteed and must therefore be evaluated by an engineer to determine their suitability.
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If notching or boring appears to be necessary to accommodate MEP elements, it is the responsibility of the affected MEP trade to request direction from the Design Professional. Furthermore it is the responsibility of the design professional to ensure the accuracy of the project documents and to make certain that the information contained in the documents will accommodate, without compromise, all building elements specified for the project.
Costs associated with the replacement, repair and/or engineering to establish an appropriate repair are the responsibility of others and not that of the framing contractor.
Additional References:
• International Building Code (IBC) Section 2210
• International Residential Code (IRC) Sections R505 & R603
• American Standard for Testing Material (ASTM) C 645-08a Standard
Specification for Nonstructural Steel Framing Members
• ASTM C 955-08 Load-Bearing (Transverse and Axial) Steel Studs,
Runners (Tracks), and Bracing or Bridging for Screw Application of
Gypsum Panel Products and Metal Plaster Bases
• The American Iron and Steel Institute North American Specification for the Design of Cold Formed Steel Structural Members (AI-
SI-S100-07)
• North American Standard for Cold Formed Steel framing General
Provisions (AISI-S 200-07)
This technical document is to serve as a guideline and it is not intended for any specific construction projects. NWCB makes no express or implied warranty or guarantee of the techniques, construction methods or materials identified herein.
www.nwcb.org
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© NORTHWEST WALL AND CEILING BUREAU