Previous Topic

Next Topic

Book Contents

Book Index

NDS 7 - Wood I-Joists

Sizer performs rudimentary design for wood I-joists according to NDS Chapter 7 as described in Materials, I-joists. The program does not allow for wet service factor CM (7.3.3), beam stability factor CL (7.3.5), or preservative treatment (7.3.7). It does allow fire retardant treatment factors and temperature factor Ct (7.3.4). The repetitive member factor Cr (7.3.6) is not applicable to I-joists, having a value of 1.0.

These conditions imply that the I-joist is used in dry service conditions, is fully supported on the compression flange, and has not been treated.

None of the special design considerations other than the evaluation of shear at the support (7.4.7) and shear deflection (7.4.5) are implemented for I-joists. Bearing design (7.4.1), web stiffeners (7.4.2), Web holes (7.4.3), notches (7.4.4), load transfer blocking (7.4.6) are not considered in the generic version of WoodWorks Sizer.

Many of these provisions are handled by customized versions of Sizer distributed by I-joist manufacturers.

Sizer implements shear deflections (7.4.5) as described under Deflection Design and Structural Analysis. In doing so, the shear constant K stored in the database for that product is used to derive the parameters GA and k used in the calculation via the relation GA / k = K / 8.

See Also

National Design Specification (NDS)

NDS 1.4 - Design Loads

NDS 3.1.2 - Net Section Area

NDS 2.3 - General Adjustment Factors

NDS 3.2 - Bending Members - General

NDS 3.3 - Bending Members - Flexure

NDS 3.4 - Bending Members - Shear

NDS 3.5 - Bending Members - Deflection

NDS 3.6 , 3.7 and C3.7.1 - Compression Members and Solid Columns

NDS C3.7.1 - Alternative Stability Factor for CLT Wall Panels

NDS 3.8 Tension Members

NDS 3.9 - Combined Bending and Axial Loading, and Biaxial Bending

NDS 3.10 - Design for Bearing

NDS 4.3 - Adjustment Factors (Sawn Lumber)

NDS 4.4 and 5.4- Special Design Considerations

NDS 5.3, Supplement Tables 5A-5D - Glulam Adjustment Factors

NDS Appendix D and Supplement Table 5- Glulam E'min

NDS 8 - Structural Composite Lumber

NDS 10.3 - CLT Adjustment Factors

NDS 10.4.1 - CLT Stiffness

NDS 15.2 and 15.3 - Spaced and Built-up Columns

NDS 15.4 - Wood Columns with Side Loads and Eccentricity

NDS C15.4 - CLT Combined Axial and Bending

NDS 16, AWC TR 10, and AWC Fire Standard - Fire Design

NDS Appendix N - LRFD Design