Close |
Lumber Span Tables |
2003 International Residential Code (IRC) |
Floor Joists- All Rooms Except Sleeping Rooms and Attics (40 PSF Live Load, 10 PSF Dead Load) L/360 |
|
2x6 |
2x8 |
2x10 |
2x12 |
Species and Grade |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
#1/#2 Doug Fir/Larch North |
10'9 |
9'9 |
8'0 |
14'2 |
12'5 |
10'2 |
17'6 |
15'2 |
12'5 |
20'4 |
17'7 |
14'4 |
#2 Doug Fir/Larch (US) |
10'9 |
9'9 |
8'1 |
14'2 |
12'7 |
10'3 |
17'9 |
15'5 |
12'7 |
20'7 |
17'10 |
14'7 |
#1/#2 Hem Fir North |
10'9 |
9'9 |
8'6 |
14'2 |
12'10 |
11'0 |
18'0 |
16'5 |
13'5 |
21'11 |
19'1 |
15'7 |
#2 Hem Fir (US) |
10'0 |
9'1 |
7'11 |
13'2 |
12'0 |
10'2 |
16'10 |
15'2 |
12'5 |
20'4 |
17'7 |
14'4 |
#1/#2 Spruce/Pine/Fir North |
10'3 |
9'4 |
8'1 |
13'6 |
12'3 |
10'3 |
17'3 |
15'5 |
12'7 |
20'7 |
17'10 |
14'7 |
Decks #2 PT So. Yel. Pine. (SPC) |
10'4 |
9'5 |
7'10 |
13'8 |
12'5 |
10'2 |
17'5 |
15'10 |
13'1 |
21'2 |
18'10 |
15'5 |
Floor Joists- Sleeping Rooms and Attics (30 PSF Live Load, 10 PSF Dead Load) L/360 |
|
2x6 |
2x8 |
2x10 |
2x12 |
Species and Grade |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
#1/#2 Doug Fir/Larch North |
11'10 |
10'9 |
8'11 |
15'7 |
13'11 |
11'4 |
19'7 |
16'11 |
13'10 |
22'8 |
19'8 |
16'1 |
#2 Doug Fir/Larch (US) |
11'10 |
10'9 |
9'1 |
15'7 |
14'1 |
11'6 |
19'10 |
17'2 |
14'1 |
23'0 |
19'11 |
16'3 |
#1/#2 Hem Fir North |
11'10 |
10'9 |
9'4 |
15'7 |
14'2 |
12'4 |
19'10 |
18'0 |
15'0 |
24'2 |
21'4 |
17'5 |
#2 Hem Fir (US) |
11'0 |
10'0 |
8'9 |
14'6 |
13'2 |
11'4 |
18'6 |
16'10 |
13'10 |
22'6 |
19'8 |
16'1 |
#1/#2 Spruce/Pine/Fir |
11'3 |
10'3 |
8'11 |
14'11 |
13'6 |
11'6 |
19'0 |
17'2 |
14'1 |
23'0 |
19'11 |
16'3 |
Ceiling Joists- Drywall- No Future Rooms, Limited Storage: (20 PSF Live Load, 10 PSF Dead Load) L/240 |
|
2x4 |
2x6 |
2x8 |
2x10 |
Species and Grade |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
#1/#2 Doug Fir/Larch North |
9'10 |
8'8 |
7'1 |
14'7 |
12'8 |
10'4 |
18'6 |
16'0 |
13'1 |
22'7 |
19'7 |
16'0 |
#2 Doug Fir/Larch (US) |
9'10 |
8'11 |
7'3 |
15'0 |
13'0 |
10'8 |
19'1 |
16'6 |
13'6 |
23'3 |
20'2 |
16'5 |
#1/#2 Hem Fir North |
9'10 |
8'11 |
7'8 |
15'6 |
13'9 |
11'2 |
20'1 |
17'5 |
14'2 |
24'6 |
21'3 |
17'4 |
#2 Hem Fir (US) |
9'2 |
8'4 |
7'1 |
14'5 |
12'8 |
10'4 |
18'6 |
16'0 |
13'1 |
22'7 |
19'7 |
16'0 |
#1/#2 Spruce/Pine/Fir |
9'5 |
8'7 |
7'2 |
14'9 |
12'10 |
10'6 |
18'9 |
16'3 |
13'3 |
22'11 |
19'10 |
16'3 |
Rafters- Snow Region Light Roof covering, Drywall, No Attic Space (30 PSF Live Load, 10 PSF Dead Load) L/240 |
|
2x6 |
2x8 |
2x10 |
2x12 |
Species and Grade |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
#1/#2 Doug Fir/Larch North |
13'6 |
11'9 |
9'7 |
17'2 |
14'11 |
12'2 |
21'0 |
18'2 |
14'10 |
24'4 |
21'1 |
17'3 |
#2 Doug Fir/Larch (US) |
13'2 |
11'5 |
9'4 |
16'8 |
14'5 |
11'9 |
20'4 |
17'8 |
14'5 |
23'7 |
20'5 |
16'8 |
#1/#2 Hem Fir North |
13'6 |
12'3 |
10'5 |
17'10 |
16'2 |
13'2 |
22'9 |
19'9 |
16'1 |
26'5 |
22'10 |
18'8 |
#2 Hem Fir (US) |
12'7 |
11'1 |
9'1 |
16'2 |
14'0 |
11'6 |
19'10 |
17'2 |
14'0 |
22'11 |
19'11 |
16'3 |
#1/#2 Spruce/Pine/Fir |
12'11 |
11'9 |
9'9 |
17'0 |
15'1 |
12'4 |
21'4 |
18'5 |
15'1 |
24'8 |
21'5 |
17'6 |
Rafters- Snow Region Light Roof covering, (30 PSF Snow Load, 10 PSF Dead Load) L/180 No Finished Ceiling |
|
2x6 |
2x8 |
2x10 |
2x12 |
Species and Grade |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
12" oc |
16" oc |
24" oc |
#1/#2 Doug Fir/Larch North |
13'7 |
11'9 |
9'7 |
17'2 |
14'11 |
12'2 |
21'0 |
18'2 |
14'10 |
24'4 |
21'1 |
17'3 |
#2 Doug Fir/Larch (US) |
14'0 |
12'1 |
9'10 |
17'8 |
15'4 |
12'6 |
21'7 |
18'9 |
15'3 |
24'8 |
21'5 |
17'6 |
#1/#2 Hem Fir North |
14'9 |
12'9 |
10'5 |
18'8 |
16'2 |
13'2 |
22'9 |
19'9 |
16'1 |
26'5 |
22'10 |
18'8 |
#2 Hem Fir (US) |
13'7 |
11'9 |
9'7 |
17'2 |
14'11 |
12'2 |
21'0 |
18'2 |
14'10 |
24'4 |
21'1 |
17'3 |
#1/#2 Spruce/Pine/Fir |
13'9 |
11'11 |
9'9 |
17'5 |
15'1 |
12'4 |
21'4 |
18'5 |
15'1 |
24'8 |
21'5 |
17'6 |
|
Roof Pitch |
15 |
14 |
13 |
12 |
11 |
10 |
9 |
8 |
7 |
6 |
5 |
4 |
Slope Factor |
1.601 |
1.537 |
1.474 |
1.414 |
1.357 |
1.302 |
1.25 |
1.202 |
1.158 |
1.118 |
1.083 |
1.054 |
Roof Coverage = slope Factor x sq footage of foot print under the roof
Example: 25x40 colonial with 6/12 pitch would need 1,000 sf (footprint) x 1.118 (Slope Factor) = 1,118 sf on the roof. (11.18 squares of roofing) |
This table is only a guide and should not be substituted for the Building Code.
Spans are taken from "The U.S. Span Book for Major Lumber Species" 2002 Edition http://www.cwc.ca
Southern Pine Council "Pressure Treated Southern Pine" Standards Specifications and Applications Guide http://www.southernpine.com |
Last Updated on Oct 31, 2005 |