1) Applies to nominally dimensioned joists as listed, where moisture content < 19% and temperature <100°F.
2) Loads apply to:
DF-L: Douglas Fir-Larch (G=0.50), Fv=180 psi;
SP: Southern Pine (G=0.55), Fv=175 psi;
S-P-F: Spruce-Pine-Fir (G=0.42), Fv=135 psi;
Hem Fir (G=0.43), Fv=150 psi
3) 115% and 125% loads are increased for short-term loading in accordance to the code.
ROOF PITCH CHART
If common Rafter Roof Pitch is...
Rise / Run (inches)
Slope (degrees)
1/12
5
2/12
10
3/12
14
4/12
18
5/12
23
6/12
27
7/12
30
8/12
34
9/12
37
10/12
40
11/12
42
12/12
45
Then Hip/Valley Rafter Roof Pitch becomes...
Rise / Run (inches)
Slope (degrees)
1/17
3
2/17
7
3/17
10
4/17
13
5/17
16
6/17
19
7/17
22
8/17
25
9/17
28
10/17
30
11/17
33
12/17
35
1) Use this conversion table only for hip/valley rafters that are skewed 45° right or left. All other skews or dual pitch roofs will cause the slope to change from that listed above.
SLOPE CONVERSION TABLE
Rise / Run (inches)
Slope (degrees)
0/12
Flat
1/12
5
2/12
10
3/12
14
4/12
18
5/12
23
6/12
27
7/12
30
8/12
34
9/12
37
10/12
40
11/12
42
12/12
45
U.S. STANDARD STEEL GAUGE EQUIVALENTS IN NOMINAL DIMENSION
Gauge
Approximate Dimensions
Decimals (inches)
Inches
Millimeters
Uncoated Steel
Galvanized Steel (G90)
Triple Zinc
3
1/4
6.0
0.239
-- --
-- --
7
3/16
4.5
0.179
0.186
-- --
10
9/64
3.4
0.134
0.138
0.140
11
1/8
3.0
0.120
0.123
0.125
12
7/64
2.7
0.105
0.108
0.110
14
5/64
2.0
0.075
0.078
0.080
16
1/16
1.5
0.060
0.063
0.065
18
3/64
1.2
0.048
0.052
0.054
20
1/32
1.0
0.036
0.040
0.042
22
1/32
0.8
0.030
0.033
0.036
*Actual steel dimensions will vary from nominal dimensions according to industry tolerances.
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