WESTERN LUMBER STRUCTURAL GRADES
WWPA Western Lumber
Grading Rules
Section Reference
Product
Grades
WESTERN LUMBER DIMENSION GRADES
Structural Light
SELECT STRUCTURAL
(42.10)
Framing (SLF)
NO. 1
(42.11)
2" to 4" thick
NO. 2
(42.12)
2" to 4" wide
NO. 3
(42.13)
Light Framing (LF)
CONSTRUCTION
(40.11)
2" to 4" thick
STANDARD
(40.12)
2" to 4" wide
UTILITY
(40.13)
Stud
STUD
(41.13)
2" to 4" thick
2" and wider
Structural Joists
SELECT STRUCTURAL
(62.10)
and Planks (J&P)
NO. 1
(62.11)
NO. 2
(62.12)
NO. 3
(62.13)
WESTERN LUMBER STRUCTURAL DECKING GRADES
Structural Decking
SELECTED DECKING
(55.11)
2" to 4" thick
4" to 12" wide
COMMERCIAL DECKING
(55.12)
WESTERN LUMBER TIMBER GRADES
Beams and Stringers DENSE SELECT
5" and thicker,
STRUCTURAL*
width more than
DENSE NO. 1*
2" greater than
DENSE NO. 2*
thickness
SELECT STRUCTURAL
NO. 1
NO. 2
Post and Timbers
DENSE SELECT
5" x 5" and larger,
STRUCTURAL*
width not more
DENSE NO. 1*
than 2" greater
DENSE NO. 2*
than thickness
SELECT STRUCTURAL
NO. 1
NO. 2
(53.00 & 170.00)
(53.00 & 170.00)
(53.00 & 170.00)
(70.10)
(70.11)
(70.12)
(53.00 & 170.00)
(53.00 & 170.00)
(53.00 & 170.00)
(80.10)
(80.11)
(80.12)
*Douglas Fir or Douglas Fir-Larch only.
©1997
Western Wood Products Association
Uses/End Uses
Structural applications
where highest design
values are needed in light
framing sizes.
Where high-strength values are not
required, such as wall framing, plates,
sills, cripples, blocking, etc.
An optional all-purpose grade
designed primarily for stud uses,
including bearing walls.
Used where the appearance of the
best face is of primary importance.
Customarily used when appearance
is not of primary importance.
Grades are designed for beam
and stringer type uses when
sizes larger than 4" nominal
thickness are required.
Grades are designed for vertically
loaded applications where sizes
larger than 4" nominal thickness
are required.