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The following parameters can be defined for the sheathing applied to the sides of a shear wall in Wall Input View. Refer to the topics under Provisions by Sheathing Material Type for detailed tables showing the choices of wall materials available in Shearwalls.
Sheathing Material - you must select a material from list of materials in design code tables. Changing the material refreshes the choices for all other inputs in the dialog.
Sheathing Thickness - The program provides a list of standard plywood thicknesses from the design code tables. You can enter a different thickness yourself and the program will design for the closest thickness less than the one you selected, so this input can be considered a minimum thickness. Plywood is not manufactured in other thicknesses, so there is little need to enter a thickness other than one in the list.
Sheathing thickness can be unknown. Changing the thickness refreshes the choices for span rating and nail size.
Orientation of long side of panel - For structural wood panels, this is vertical or horizontal. The orientation primarily affects wind component and cladding out-of-plane bending design, but there are certain exceptions for shear wall strengths that depend on orientation. For lumber sheathing, the orientation can also be diagonal or double-diagonal, and orientation affects shear strength.
Span Rating – The span rating is linked to the sheathing thickness according to SDPWS Table C4.2.2C. The program both the primarly and alternative span ratings for each thickness, defaulting to the primary. The value for shear stiffness GvTv from table C4.2.2A is based on selected span rating, not the selected thickness.
Plies - No. of plywood plies used to select shear stiffness Gvtv value for deflection design from SDPWS Table C4.2.2.2A
OSB - A checkbox indicates whether the structural material chosen is OSB, so that it uses the shear stiffness values Gvtv from SDPWS Table C4.2.2.2A for OSB.
Blocking - This check box indicates whether the sheathing panel edges on the selected side or sides are nailed to blocking. Note that vertically oriented panels are still considered to be unblocked unless they are staggered such that there are horizontal seams to be blocked.
An unblocked factor is applied to shear strength and deflection calculations for unblocked structural wood panels. Gypsum wallboard has different shear design values depending on whether it is blocked or unblocked.
Blocking - For structural panels, blocking is linked with edge nail spacing, due to the requirement that only 6" edge spacing can be unblocked. If 4,3, and 2" spacings do not appear, then you have to check blocking to make them appear . If blocking is disabled, then you have to change to 6" spacing to enable it.