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.