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Joists
Sawn Lumber Sizes
Sawn lumber used as joists ranges in common thicknesses from 2 to 4 in. (51 to 102 mm) and in depths from 4 to 12 in. (102 to 305 mm). 4-inch thick members are available in 14" and 16" depths as well. They are the most economical and easily installed secondary framing members for floor and roof construction in spans up to approximately 23 ft. (7m)
Actual sizes for design as compared with nominal sizes are given in NDS Table 1A, using dry sizes for design in all conditions.
Species and Grades
Sizer includes all softwood and hardwood species listed in the NDS Supplement. Southern Pine, S-P-F, Hem-Fir and D.Fir-L are most likely to be stocked by lumber yards, but other species may also be on hand. These "major" species are in a separate material selection called Lumber soft; less common selections are in Lumber-other and hardwood in Lumber-hard.
In the 2 in. (51mm) thickness, the most readily obtainable grade is No.1 or No.2.
MSR and MEL Sizes and Grades
Sizer includes all Machine Stress-Rated and Machine-Evaluated grades listed in the NDS Supplement, with the same depths as visually graded lumber, but only 2" widths. The 3 and 4 in. (76 and 102 mm) thicknesses thicknesses are generally surfaced in the green condition (S-Grn) and are not obtainable as MSR lumber. Joists in 2 in. (51mm) thickness can usually be obtained kiln-dried (specify S-Dry) to a moisture content of 19% or less
Suppliers tend to carry a limited range of grades, but Some MSR and MEL grades are readily available in depths up to 8 in. (203mm); wider material may not be available.
Multi-ply Joists
The program includes a database of 2" thick joists to be used in multi-ply applications, limiting the number of plies to 2. This allows you to double up the joist members to deal with heavy loading requirements.
Beams
Sizer includes a material selection for beams with the same species, grades, and sizes as in the lumber-soft major species selection for joists. This is included in case you want to design a member in isolation, not part of a system of joists.
Stud Walls
Sizes
Lumber used in stud wall systems has a common thickness of 2 in. (51mm) and ranges in depth from 4 to 8 in. (102 to 203mm). Stud grade lumber, however, ranges in depths from 2 to 6 in. (51 to 152mm); the smaller sizes are used mainly in partitions. For depths greater than 6 in. (152mm), another grade must be specified.
Sheathing Requirements
In stud walls the members are spaced no farther apart than 24 in. (610mm) to take advantage of load sharing. Usually the spacing is 16 in. (406mm) or less. Stud wall systems are typically sheathed by plywood, waferboard, oriented strandboard or drywall. The sheathing is nailed to the narrow faces of the studs (on at least one side) along the entire length of the stud, thereby preventing buckling about the weak axis.
Note: Studs are susceptible to buckling if heavy loads are applied prior to installation of the sheathing.
Multi-ply Wall Studs
The program includes a database of 2" wall studs to be used in multi-ply applications. This allows you to for example double up the stud members to deal with heavy loading requirements.
Posts
The Sizer database includes a column selection called Lumber Posts consisting of 4 wide members in 4, 6 and 8 inch depths, containing major species only.