CSA O86 Provisions

Shearwalls implements the following provisions related to shear wall design from Chapter 11 of CSA O86 :

• The following provisions from 11.3 Design for light frame shear walls:
  • 11.3.2 - Framing and Sheathing - Reflected in the wall material choices and notes to the Sheathing and Framing Materials table. ,
  • 11.3.3.1- Gypsum Wallboard Requirements
• The following provisions from 11.4 Design considerations for light frame shearwalls
  • 11.4.1.2 - Maximum height-to-width ratio for shearwall segment
  • 11.4.2.1 - Summing capacities of shear walls in shear line with dissimilar materials
  • 11.4.3.1 - Use of gypsum wallboard underlay with no increase in strength
  • 11.4.3.2 - Summing capacities of different sheathing materials on either side of wall
  • 11.4.4 - Overturning restraint
• The following following modification factors from 11.5:
  • 11.5.1 - Fastener spacing factor J_s
  • 11.5.4 - Unblocked factor J_us
  • 11.5.5 - Hold-down effect factor J_hd
• The following provisions from 11.6 - Shear resistance of shearwalls:
  • 11.6.2.2 - Shear resistance equations for wood structural panels based on the worst case of lateral nail resistance and panel bending
  • 11.6.2.3 - Shear resistance equations for gypsum wallboard
  • Table 11.4 - Shear Strength for Gypsum Wallboard Shear Walls
  • 11.6.4 - Moment resistance of shearwalls. See Overturning restraint. Hold-down devices are specified and designed; shearwall end chords are not.
• 11.7 - Deflection of light frame shearwalls - See Deflection Analysis
• The following provisions from 11.8 - Seismic design considerations
  • 11.8.1 - Non-ductile design modes
  • 11.8.2 - Hold-down force amplification
  • 11.8.3 - Overcapacity of seismic force resisting system
  • 11.8.6 - Design of force transfer elements
  • 11.8.8 - Requirements when Using Gypsum Wallboard,
  • Table 11.6 - Maximum percentage of gypsum wallboard

The following information and procedures from other parts of the O86 are also required:

• Tables 9.1-9.3 - Strength, Stiffness and Rigidity Properties for Plywood and OSB; used for:
  • Determining materials and thicknesses available for selection and design
  • Calculation of panel bending mode of shear wall resistance of from 11.6.2.2(b)
  • Calculation of the panel shear component of deflection equation
  • Thicknesses used in nail resistance equations in 12.9.3.2 (see below)
• 12.9.3.1 - Lateral nail resistance, general
  • Provides shearwall construction factor J_D = 1.3 applied to factored lateral nail resistance N_u used in nailing mode of shearwall resistance in 11.6.2.2(a)
  • Provides relevant modification K-factors for N_u used for the same purpose
• 12.9.3.2 - Unit lateral nail resistance n_u
  • N_u = n_u x factors used in nailing mode of shear resistance V_rs in 11.6.2.2(a)
  • n_u used directly in calculation of shear wall deflection for anchorages
• 12.9.4.2 - Used for nail withdrawal resistance P_rw for C&C design,
• A11.7 - Equation for nail deformation e_n in nail slip component of deflection equation
• Table A.8 - Panel Marking for Construction Sheathing Products and Table A.9 Relationship between Panel Marking and Thickness
  • Defining OSB materials and thicknesses available for selection and design
  • Provides OSB panel marking to index table 9.3 for OSB design properties
• Table A.11 - Provides specific gravity of sheathing materials for nail strength calculations
• Table A.21 - CSA B111 Nail sizes
• Table A.22 - ASTM F1667 Nail sizes
• Table A.23 Service Creep Factor K_m - Used in calculation of deflection for anchorages