• Allowable HOW composite limiting heights were tested in accordance with AISI S916 and ICC-ES AC86.
• The tests were modified from the standards with the tracks fastened to the test fixture such that the wall stiffness included the track deformation.
• In accordance with current building codes and AISI design standards, the 1/3 Stress Increase for strength was not used.
• The composite limiting heights provided in the tables are based on a single layer of 5/8" Type X Gypsum Board from the following manufacturers: American, CertainTeed, Georgia Pacific, Continental, National, PABCO, and USG.
• The gypsum board must be applied full height in the vertical orientation to each stud flange and installed in accordance with ASTM C754 using minimum No. 6 Type S Drywall screws spaced as listed below:
  • Sheathing screws spaced a maximum of 16 in on-center to framing members (including bottom track) when studs spaced at 16 in or 12 in on-center.
  • Sheathing screws spaced a maximum of 12 in on-center to framing members (including bottom track) when studs spaced at 24 in on-center.
• #8 wafer head screws shall be used for attaching the stud to 30mil 2-1/2" Leg MaxTRAK (as top track) adhering to details below:
  • Stud to track connection must be installed as depicted in figure with a maximum gap of 7/8" between the web of the MaxTRAK and end of stud.
  • Slots in the MaxTRAK Legs allows for a total vertical movement of 1-1/2" (+/- 3/4") with screw centered in slots.
  • Screws shall be placed in each flange of the stud at a minimum of 3/8" from the end of the stud.
  • To permit head of wall deflection, gypsum board must not be fastened directly to the MaxTRAK.

• No fasteners are required for attaching the stud to the bottom track except as detailed in ASTM C754.

  f Adjacent to the height value indicates that flexural stress controls the allowable wall height.

Note: Users of this design tool should check the actual details of construction for the selected assembly to achieve the required fire and/or sound rating. Details of construction may be obtained from engineering evaluations, or listings from recognized fire testing and sound laboratories. For links to the test reports click on the Fire or STC ratings in the selected wall systems above.

• 3-1/2", 4”, 5-1/2” & 6” stud depth STC ratings are based on sound testing conducted on 3-5/8" stud depth. Wider stud depths may result in better STC points. (Based on Veneklasen Associates, Inc. ProSTUD acoustical analysis 5123-019-3B)

• 16"o.c. & 12"o.c. STC ratings are an interpolation of 24"o.c. STC ratings. (Based on Veneklasen Associates, Inc. ProSTUD acoustical analysis 5123-019-4B)