ASD/LRFD Manual - American Wood Council
ASD/LRFD Manual - American Wood Council
ASD/LRFD Manual - American Wood Council
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12 M4: SAWN LUMBER<br />
M4.1 General<br />
Product Information<br />
Structural lumber products are well-known throughout<br />
the construction industry. The economic advantages<br />
of lumber often dictate its choice as a preferred building<br />
material.<br />
Lumber is available in a wide range of species, grades,<br />
sizes, and moisture contents. Structural lumber products<br />
are typically specified by either the stress level required<br />
or by the species, grade, and size required.<br />
This Chapter provides information for designing structural<br />
lumber products in accordance with the NDS.<br />
Common Uses<br />
Structural lumber and timbers have been a primary<br />
construction material throughout the world for many centuries.<br />
They are the most widely used framing material for<br />
housing in North America.<br />
In addition to use in housing, structural lumber finds<br />
broad use in commercial and industrial construction. Its<br />
high strength, universal availability, and cost saving attributes<br />
make it a viable option in most low- and mid-rise<br />
construction projects.<br />
Structural lumber is used as beams, columns, headers,<br />
joists, rafters, studs, and plates in conventional construction.<br />
In addition to its use in lumber form, structural lumber<br />
is used to manufacture structural glued laminated beams,<br />
trusses, and wood I-joists.<br />
Availability<br />
Structural lumber is a widely available construction<br />
material. However, to efficiently specify structural lumber<br />
for individual construction projects, the specifier should be<br />
aware of the species, grades, and sizes available locally.<br />
The best source of this information is your local lumber<br />
supplier.<br />
M4.2 Reference Design Values<br />
General<br />
The NDS Supplement provides reference design values<br />
for design of sawn lumber members. These design values<br />
are used when manual calculation of member capacity is<br />
required and must be used in conjunction with the adjustment<br />
factors specified in NDS 4.3.<br />
Reference Design Values<br />
Reference design values are provided in the NDS<br />
Supplement as follows:<br />
NDS<br />
Supplement<br />
Table Number<br />
4A and 4B<br />
4C<br />
4D<br />
4E<br />
4F<br />
Visually graded dimension lumber<br />
Mechanically graded dimension lumber<br />
Visually graded timbers<br />
Visually graded decking<br />
Non-North <strong>American</strong> visually graded<br />
dimension lumber<br />
<strong>American</strong> <strong>Wood</strong> <strong>Council</strong>
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