ALLOWABLE LOAD TABLES
— BEAMS AND GIRDERS
These allowable load tables (Table 12,
Table 13, and Table
14) are intended as guidelines to provide the user with
an idea of the maximum loads in pounds per lineal foot (plf)
for various wood products with girder spans common in raised
floor systems. These allowable loads were determined in accordance
with appropriate standards, such as the National Design Specification®
(NDS®) for Wood Construction published by the
American Forest & Paper Association. They are based on uniform,
gravity loads only, and assume dry-service conditions. For more
complete allowable load table information, refer to Southern
Pine Hearders and Beams.
Treated Southern Pine 4x6 sill beams
are supported by concrete block piers on a continuous spread footing.
KEY For each span, there are three rows of numbers:
Row 1:
Maximum total load in pounds
per lineal foot with deflection limited to
ℓ/240
Row 2:
Maximum live load in pounds
per lineal foot with deflection limited to
ℓ/360
Row 3:
Required bearing length in
1.5" trimmer thickness increments
Table
12 Solid-Sawn No. 2 Southern Pine
Span feet
Size(nominal inches)
4x6
6x6
6x8
8
223
221
1.5
237
237
1.5
412
412
1.5
10
142
114
1.5
149
137
1.5
262
262
1.5
12
95
66
1.5
102
80
1.5
179
179
1.5
Source:
Southern Pine Council. See KEY for explanation
of table values.
Table
13 24F-V3 Southern Pine Glued Laminated Timber, 3-1/2"
Width
SPAN
TABLES — FLOOR JOISTS AND TRUSSES
These span tables (Table 15, Table
16, Table 17, and Table
18) are intended as guidelines to provide the user with
an idea of the maximum spans in feet and inches for various
wood products with floor loads common in raised floor systems.
These spans were determined in accordance with appropriate standards,
such as the National Design Specification® (NDS®)
for Wood Construction published by the American Forest &
Paper Association and the National Design Specification for
Metal Plate Connected Wood Truss Construction published
by the Truss Plate Institute. They are based on uniform, gravity
loads only, and assume dry-service conditions. For more complete
span table information, refer to Maximum
Spans for Joists and Rafters, www.awc.org,
or www.woodtruss.com.
Table
15 Floor Joists — Solid-Sawn Southern Pine Lumber
40 psf live load, 10 psf dead load,
ℓ/360 deflection
10 psf dead load top chord, 5 psf
deal load bottom chord
Depth inches
Spacing inches on center
Grade
SS/No.1 DNS feet-inches
No.1 feet-inches
No.2 feet-inches
12
24
16-
11
16-
8
16-
1
14
24
19-
2
18-
11
17-
11
16
24
27-
6
21-
2
19-
2
Source: Wood Truss Council of
America (www.woodtruss.com).
Assumes bottom-chord bearing. SS = Select Structural. DNS =
Dense.
Table
18 Floor Trusses with Southern Pine Lumber
50 psf live load — Commercial
15 psf dead load top chord, 10 psf
deal load bottom chord
Depth inches
Spacing inches on center
Grade
SS feet-inches
No.1 feet-inches
No.2 feet-inches
16
24
24-
3
19-
1
16-
3
18
24
27-
0
21-
5
17-
10
20
24
29-
6
23-
3
19-
8
Source: Wood Truss Council of
America (www.woodtruss.com).
Assumes bottom-chord bearing. SS = Select Structural. DNS =
Dense. Table 18 includes a 20 pound per square foot (psf) partition
load and a 2000 pound concentrated load per the 2000 International
Building Code, sections 1607.5 and 1607.1 respectively.
