TABLE 1-1. Nominal Sizes and Dressed Sizes of
TABLE 1-2. Nominal Sizes and Dressed Sizes of
Lumber (New Standard)
Lumber (Old Standard)
greater. Table 1-2 gives the nominal and dressed
a. Select lumber. Select lumber is of
sizes that were in use prior to adoption of the
good appearance and finish, and is identified by the
standards indicated in table 1-1. Lumber dressed to
the dimensions shown in table 1-2 may still appear in
some areas and certainly lumber of both finished
(1) Grade A. Grade A is suitable for
dimensions will be used and the dimensions must be
natural finishes and practically clear.
given consideration in repair and modification work
(2) Grade B. Grade B is suitable for
involving existing framed structures.
natural finishes, of high quality, and generally clear.
1-16. GRADES OF LUMBER
(3) Grade C. Grade C is adapted to
Lumber as it comes from the sawmill is divided
high quality paint finishes.
into three main classes: yard lumber, structural
(4) Grade D. Grade D is suitable for
material, and factory and shop lumber. In keeping
paint finishes between higher finishing grades and
with the purpose of this subcourse, only yard lumber
common grades, and contains somewhat the nature of
will be considered. Yard lumber is manufactured and
classified, on a quality basis, into those sizes, shapes,
and qualities required for ordinary construction and
b. Common lumber. Common lumber is
genera building purposes including TO construction.
suitable for general construction and utility purposes
It is subdivided into classifications of select lumber
and is identified by the following grade names:
and common lumber.
(1) No. 1 common. No. 1 common is
suitable for use without waste; it is sound and tight-
knotted; and it may be considered watertight lumber.