UpCodes logo
Jump To Full Code Chapter
The fire-resistance ratings of structural steel columns shall be based on the size of the element and the type of protection provided in accordance with this section.
TABLE 722.5.1(1)
W/D RATIOS FOR STEEL COLUMNS
STRUCTURAL SHAPE CONTOUR PROFILE BOX PROFILE
W14 × 233 2.55 3.65
× 211 2.32 3.35
× 193 2.14 3.09
× 176 1.96 2.85
× 159 1.78 2.60
× 145 1.64 2.39
× 132 1.56 2.25
× 120 1.42 2.06
× 109 1.29 1.88
× 99 1.18 1.72
× 90 1.08 1.58
× 82 1.23 1.68
× 74 1.12 1.53
× 68 1.04 1.41
× 61 0.928 1.28
× 53 0.915 1.21
× 48 0.835 1.10
× 43 0.752 0.99
W12 × 190 2.50 3.51
× 170 2.26 3.20
× 152 2.04 2.90
× 136 1.86 2.63
× 120 1.65 2.36
× 106 1.47 2.11
× 96 1.34 1.93
× 87 1.22 1.76
× 79 1.11 1.61
× 72 1.02 1.48
× 65 0.925 1.35
× 58 0.925 1.31
× 53 0.855 1.20
× 50 0.909 1.23
× 45 0.829 1.12
× 40 0.734 1.00
W10 × 112 1.81 2.57
× 100 1.64 2.33
× 88 1.45 2.08
× 77 1.28 1.85
× 68 1.15 1.66
× 60 1.01 1.48
× 54 0.922 1.34
× 49 0.84 1.23
× 45 0.888 1.24
× 39 0.78 1.09
× 33 0.661 0.93
W8 × 67 1.37 1.94
× 58 1.20 1.71
× 48 1.00 1.44
× 40 0.849 1.23
× 35 0.749 1.08
× 31 0.665 0.97
× 28 0.688 0.96
× 24 0.591 0.83
× 21 0.577 0.77
× 18 0.499 0.67
W6 ×25 0.696 1.00
× 20 0.563 0.82
× 16 0.584 0.78
× 15 0.431 0.63
× 12 0.448 0.60
× 9 0.338 0.46
W5 ×19 0.644 0.93
× 16 0.55 0.80
W4 ×13 0.556 0.79
For SI: 1 pound per linear foot per inch = 0.059 kg/m/mm.

FIGURE 722.5.1(1)
DETERMINATION OF THE HEATED PERIMETER OF STRUCTURAL STEEL COLUMNS
 
TABLE 722.5.1(2)
PROPERTIES OF CONCRETE
PROPERTY NORMAL-WEIGHT CONCRETE STRUCTURAL LIGHTWEIGHT CONCRETE
Thermal conductivity (kc) 0.95 Btu/hr × ft × °F 0.35 Btu/hr × ft × °F
Specific heat (cc) 0.20 Btu/lb °F 0.20 Btu/lb °F
Density (Pc) 145 lb/ft3 110 lb/ft3
Equilibrium (free) moisture content (m) by volume 4% 5%
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 lb/ft3= 16.0185 kg/m3, Btu/hr × ft × °F = 1.731 W/(m × K).
 
 For SI: 1 inch = 25.4 mm, 1 foot = 305 mm.
  1. Structural steel column, either wide flange or tubular shapes.
  2. Type X gypsum board or gypsum panel products in accordance with ASTM C1177, C1178, C1278, C1396 or C1658. The total thickness of gypsum board or gypsum panel products calculated as h in Section 722.5.1.2 shall be applied vertically to an individual column using one of the following methods:
    1. As a single layer without horizontal joints.
    2. As multiple layers with horizontal joints not permitted in any layer.
    3. As multiple layers with horizontal joints staggered not less than 12 inches vertically between layers and not less than 8 feet vertically in any single layer. The total required thickness of gypsum board or gypsum panel products shall be determined on the basis of the specified fire-resistance rating and the weight-to-heated-perimeter ratio (W/D) of the column. For fire-resistance ratings of 2 hours or less, one of the required layers of gypsum board or gypsum panel product may be applied to the exterior of the sheet steel column covers with 1-inch long Type S screws spaced 1 inch from the wallboard edge and 8 inches on center. For such installations, 0.0149-inch minimum thickness galvanized steel corner beads with 11/2-inch legs shall be attached to the wallboard with Type S screws spaced 12 inches on center.
  3. For fire-resistance ratings of 3 hours or less, the column covers shall be fabricated from 0.0239-inch minimum thickness galvanized or stainless steel. For 4-hour fire-resistance ratings, the column covers shall be fabricated from 0.0239-inch minimum thickness stainless steel. The column covers shall be erected with the Snap Lock or Pittsburgh joint details. For fire-resistance ratings of 2 hours or less, column covers fabricated from 0.0269-inch minimum thickness galvanized or stainless steel shall be permitted to be erected with lap joints. The lap joints shall be permitted to be located anywhere around the perimeter of the column cover. The lap joints shall be secured with 1/2-inch-long No. 8 sheet metal screws spaced 12 inches on center. The column covers shall be provided with a minimum expansion clearance of 1/8 inch per linear foot between the ends of the cover and any restraining construction.
FIGURE 722.5.1(2)
GYPSUM-PROTECTED STRUCTURAL STEEL COLUMNS WITH SHEET STEEL COLUMN COVERS
 
TABLE 722.5.1(3)
THERMAL CONDUCTIVITY OF CONCRETE OR CLAY MASONRY UNITS
DENSITY (dm) OF UNITS (lb/ft3) THERMAL CONDUCTIVITY (K) OF UNITS (Btu/hr • ft • °F)
Concrete Masonry Units
80 0.207
85 0.228
90 0.252
95 0.278
100 0.308
105 0.340
110 0.376
115 0.416
120 0.459
125 0.508
130 0.561
135 0.620
140 0.685
145 0.758
150 0.837
Clay Masonry Units
120 1.25
130 2.25
For SI: 1 pound per cubic foot = 16.0185 kg/m3, Btu/hr × ft × °F = 1.731 W/(m × K)
For SI: 1 inch = 25.4 mm, 1 foot = -305 mm.
  1. Structural steel column, either wide flange or tubular shapes.
  2. 15/8-inch deep studs fabricated from 0.0179-inch minimum thickness galvanized steel with 15/16 or 17/16-inch legs. The length of the steel studs shall be 1/2 inch less than the height of the assembly.
  3. Type X gypsum board or gypsum panel products in accordance with ASTM C1177, C1178, C1278, C1396 or C1658. The total thickness of gypsum board or gypsum panel products calculated as h in Section 722.5.1.2 shall be applied vertically to an individual column using one of the following methods:
    1. As a single layer without horizontal joints.
    2. As multiple layers with horizontal joints not permitted in any layer.
    3. As multiple layers with horizontal joints staggered not less than 12 inches vertically between layers and not less than 8 feet vertically in any single layer. The total required thickness of gypsum board or gypsum panel products shall be determined on the basis of the specified fire-resistance rating and the weight-to-heated-perimeter ratio (W/D) of the column.
  4. Galvanized 0.0149-inch minimum thickness steel corner beads with 11/2- inch legs attached to the gypsum board or gypsum panel products with 1-inch-long Type S screws spaced 12 inches on center.
  5. No. 18 SWG steel tie wires spaced 24 inches on center.
  6. Sheet metal angles with 2-inch legs fabricated from 0.0221-inch minimum thickness galvanized steel.
  7. Type S screws, 1 inch long, shall be used for attaching the first layer of gypsum board or gypsum panel product to the steel studs and the third layer to the sheet metal angles at 24 inches on center. Type S screws 13/4 inches long shall be used for attaching the second layer of gypsum board or gypsum panel product to the steel studs and the fourth layer to the sheet metal angles at 12 inches on center. Type S screws 21/4 inches long shall be used for attaching the third layer of gypsum board or gypsum panel product to the steel studs at 12 inches on center.
FIGURE 722.5.1(3)
GYPSUM-PROTECTED STRUCTURAL STEEL COLUMNS WITH STEEL STUD/SCREW ATTACHMENT SYSTEM
 
TABLE 722.5.1(4)
WEIGHT-TO-HEATED-PERIMETER RATIOS (W/D) FOR TYPICAL WIDE FLANGE BEAM AND GIRDER SHAPES
STRUCTURAL SHAPE CONTOUR PROFILE BOX PROFILE
W36 × 300 2.50 3.33
× 280 2.35 3.12
× 260 2.18 2.92
× 245 2.08 2.76
× 230 1.95 2.61
× 210 1.96 2.45
× 194 1.81 2.28
× 182 1.72 2.15
× 170 1.60 2.01
× 160 1.51 1.90
× 150 1.43 1.79
× 135 1.29 1.63
W33 × 241 2.13 2.86
× 221 1.97 2.64
× 201 1.79 2.42
× 152 1.53 1.94
× 141 1.43 1.80
× 130 1.32 1.67
× 118 1.21 1.53
W30 × 211 2.01 2.74
× 191 1.85 2.50
× 173 1.66 2.28
× 132 1.47 1.85
× 124 1.39 1.75
× 116 1.30 1.65
× 108 1.21 1.54
× 99 1.12 1.42
W27 × 178 1.87 2.55
× 161 1.70 2.33
× 146 1.55 2.12
× 114 1.39 1.76
× 102 1.24 1.59
× 94 1.15 1.47
× 84 1.03 1.33
W24 × 162 1.88 2.57
× 146 1.70 2.34
× 131 1.54 2.12
× 117 1.38 1.91
× 104 1.24 1.71
× 94 1.28 1.63
× 84 1.15 1.47
× 76 1.05 1.34
W24 × 68 0.942 1.21
× 62 0.934 1.14
× 55 0.828 1.02
W21 × 147 1.87 2.60
× 132 1.68 2.35
× 122 1.57 2.19
× 111 1.43 2.01
× 101 1.30 1.84
× 93 1.40 1.80
× 83 1.26 1.62
× 73 1.11 1.44
× 68 1.04 1.35
W21 × 62 0.952 1.23
× 57 0.952 1.17
× 50 0.838 1.04
× 44 0.746 0.92
W18 × 119 1.72 2.42
× 106 1.55 2.18
× 97 1.42 2.01
× 86 1.27 1.80
× 76 1.13 1.60
× 71 1.22 1.59
× 65 1.13 1.47
× 60 1.04 1.36
× 55 0.963 1.26
× 50 0.88 1.15
× 46 0.878 1.09
× 40 0.768 0.96
× 35 0.672 0.85
W16 × 100 1.59 2.25
× 89 1.43 2.03
× 77 1.25 1.78
× 67 1.09 1.56
× 57 1.09 1.43
× 50 0.962 1.26
× 45 0.870 1.15
× 40 0.780 1.03
× 36 0.702 0.93
× 31 0.661 0.83
× 26 0.558 0.70
W14 × 132 1.89 3.00
× 120 1.71 2.75
× 109 1.57 2.52
W14 × 99 1.43 2.31
× 90 1.31 2.11
× 82 1.45 2.12
× 74 1.32 1.93
× 68 1.22 1.78
× 61 1.10 1.61
× 53 1.06 1.48
× 48 0.970 1.35
W14 × 43 0.874 1.22
× 38 0.809 1.09
× 34 0.725 0.98
× 30 0.644 0.87
× 26 0.628 0.79
× 22 0.534 0.68
W12 × 87 1.47 2.34
× 79 1.34 2.14
× 72 1.23 1.97
× 65 1.11 1.79
× 58 1.10 1.69
× 53 1.02 1.55
× 50 1.06 1.54
× 45 0.974 1.40
× 40 0.860 1.25
× 35 0.810 1.11
× 30 0.699 0.96
× 26 0.612 0.84
× 22 0.623 0.77
× 19 0.540 0.67
× 16 0.457 0.57
× 14 0.405 0.50
W10 × 112 2.17 3.38
× 100 1.97 3.07
× 88 1.74 2.75
× 77 1.54 2.45
× 68 1.38 2.20
× 60 1.22 1.97
× 54 1.11 1.79
× 49 1.01 1.64
× 45 1.06 1.59
× 39 0.94 1.40
× 33 0.77 1.20
W10 × 30 0.806 1.12
× 26 0.708 0.98
× 22 0.606 0.84
× 19 0.607 0.78
× 17 0.543 0.70
× 15 0.484 0.63
× 12 0.392 0.51
W8 × 67 1.65 2.55
× 58 1.44 2.26
× 48 1.21 1.91
× 40 1.03 1.63
× 35 0.907 1.44
× 31 0.803 1.29
× 28 0.819 1.24
× 24 0.704 1.07
× 21 0.675 0.96
× 18 0.583 0.84
× 15 0.551 0.74
× 13 0.483 0.65
× 10 0.375 0.51
W6 × 25 0.839 1.33
× 20 0.678 1.09
× 16 0.684 0.96
× 15 0.521 0.83
× 12 0.526 0.75
× 9 0.398 0.57
W5 × 19 0.776 1.24
× 16 0.664 1.07
W4 × 13 0.670 1.05
For SI: 1 pound per linear foot per inch = 0.059 kg/m/mm.
 

For SI: 1 inch = 25.4 mm, 1 pound per linear foot/inch = 0.059 kg/m/mm.
  1. The W/D ratios for typical wide flange columns are listed in Table 722.5.1(1). For other column shapes, the W/D ratios shall be determined in accordance with Section 722.5.1.1.
FIGURE 722.5.1(4)
FIRE RESISTANCE OF STRUCTURAL STEEL COLUMNS PROTECTED
WITH VARIOUS THICKNESSES OF TYPE X GYPSUM WALLBOARD
 
TABLE 722.5.1(5)
FIRE RESISTANCE OF CONCRETE MASONRY PROTECTED STEEL COLUMNS
COLUMN SIZE CONCRETE MASONRY DENSITY POUNDS PER CUBIC FOOT MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CONCRETE MASONRY PROTECTION ASSEMBLY, Te (inches)
1 hour 2 hours 3 hours 4 hours
W14 × 82 80 0.74 1.61 2.36 3.04
100 0.89 1.85 2.67 3.40
110 0.96 1.97 2.81 3.57
120 1.03 2.08 2.95 3.73
W14 × 68 80 0.83 1.70 2.45 3.13
100 0.99 1.95 2.76 3.49
110 1.06 2.06 2.91 3.66
120 1.14 2.18 3.05 3.82
W14 × 53 80 0.91 1.81 2.58 3.27
100 1.07 2.05 2.88 3.62
110 1.15 2.17 3.02 3.78
120 1.22 2.28 3.16 3.94
W14 × 43 80 1.01 1.93 2.71 3.41
100 1.17 2.17 3.00 3.74
110 1.25 2.28 3.14 3.90
120 1.32 2.38 3.27 4.05
W12 × 72 80 0.81 1.66 2.41 3.09
100 0.91 1.88 2.70 3.43
110 0.99 1.99 2.84 3.60
120 1.06 2.10 2.98 3.76
W12 × 58 80 0.88 1.76 2.52 3.21
100 1.04 2.01 2.83 3.56
110 1.11 2.12 2.97 3.73
120 1.19 2.23 3.11 3.89
W12 × 50 80 0.91 1.81 2.58 3.27
100 1.07 2.05 2.88 3.62
110 1.15 2.17 3.02 3.78
120 1.22 2.28 3.16 3.94
W12 × 40 80 1.01 1.94 2.72 3.41
100 1.17 2.17 3.01 3.75
110 1.25 2.28 3.14 3.90
120 1.32 2.39 3.27 4.06
W10 × 68 80 0.72 1.58 2.33 3.01
100 0.87 1.83 2.65 3.38
110 0.94 1.95 2.79 3.55
120 1.01 2.06 2.94 3.72
W10 × 54 80 0.88 1.76 2.53 3.21
100 1.04 2.01 2.83 3.57
110 1.11 2.12 2.98 3.73
120 1.19 2.24 3.12 3.90
W10 × 45 80 0.92 1.83 2.60 3.30
100 1.08 2.07 2.90 3.64
110 1.16 2.18 3.04 3.80
120 1.23 2.29 3.18 3.96
W10 × 33 80 1.06 2.00 2.79 3.49
100 1.22 2.23 3.07 3.80
110 1.30 2.34 3.20 3.96
120 1.37 2.44 3.33 4.12
W8 × 40 80 0.94 1.85 2.63 3.33
100 1.10 2.10 2.93 3.67
110 1.18 2.21 3.07 3.83
120 1.25 2.32 3.20 3.99
W8 × 31 80 1.06 2.00 2.78 3.49
100 1.22 2.23 3.07 3.81
110 1.29 2.33 3.20 3.97
120 1.36 2.44 3.33 4.12
W8 × 24 80 1.14 2.09 2.89 3.59
100 1.29 2.31 3.16 3.90
110 1.36 2.42 3.28 4.05
120 1.43 2.52 3.41 4.20
W8 × 18 80 1.22 2.20 3.01 3.72
100 1.36 2.40 3.25 4.01
110 1.42 2.50 3.37 4.14
120 1.48 2.59 3.49 4.28
8 × 8 × 1/2 wall thickness 80 0.77 1.66 2.44 3.13
100 0.92 1.91 2.75 3.49
110 1.00 2.02 2.89 3.66
120 1.07 2.14 3.03 3.82
8 × 8 × 3/8 wall thickness 80 0.91 1.84 2.63 3.33
100 1.07 2.08 2.92 3.67
110 1.14 2.19 3.06 3.83
120 1.21 2.29 3.19 3.98
8 × 8 × 1/4 wall thickness 80 1.10 2.06 2.86 3.57
100 1.25 2.28 3.13 3.87
110 1.32 2.38 3.25 4.02
120 1.39 2.48 3.38 4.17
6 × 6 × 1/2 wall thickness 80 0.82 1.75 2.54 3.25
100 0.98 1.99 2.84 3.59
110 1.05 2.10 2.98 3.75
120 1.12 2.21 3.11 3.91
6 × 6 × 3/8 wall thickness 80 0.96 1.91 2.71 3.42
100 1.12 2.14 3.00 3.75
110 1.19 2.25 3.13 3.90
120 1.26 2.35 3.26 4.05
6 × 6 × 1/4 wall thickness 80 1.14 2.11 2.92 3.63
100 1.29 2.32 3.18 3.93
110 1.36 2.43 3.30 4.08
120 1.42 2.52 3.43 4.22
4 × 4 × 1/2 wall thickness 80 0.93 1.90 2.71 3.43
100 1.08 2.13 2.99 3.76
110 1.16 2.24 3.13 3.91
120 1.22 2.34 3.26 4.06
4 × 4 × 3/8 wall thickness 80 1.05 2.03 2.84 3.57
100 1.20 2.25 3.11 3.88
110 1.27 2.35 3.24 4.02
120 1.34 2.45 3.37 4.17
4 × 4 × 1/4 wall thickness 80 1.21 2.20 3.01 3.73
100 1.35 2.40 3.26 4.02
110 1.41 2.50 3.38 4.16
120 1.48 2.59 3.50 4.30
6 double extra strong 0.864 wall thickness 80 0.59 1.46 2.23 2.92
100 0.73 1.71 2.54 3.29
110 0.80 1.82 2.69 3.47
120 0.86 1.93 2.83 3.63
6 extra strong 0.432 wall thickness 80 0.94 1.90 2.70 3.42
100 1.10 2.13 2.98 3.74
110 1.17 2.22 3.11 3.89
120 1.24 2.34 3.24 4.04
6 standard 0.280 wall thickness 80 1.14 2.12 2.93 3.64
100 1.29 2.33 3.19 3.94
110 1.36 2.43 3.31 4.08
120 1.42 2.53 3.43 4.22
5 double extra strong 0.750 wall thickness 80 0.70 1.61 2.40 3.12
100 0.85 1.86 2.71 3.47
110 0.91 1.97 2.85 3.63
120 0.98 2.02 2.99 3.79
5 extra strong 0.375 wall thickness 80 1.04 2.01 2.83 3.54
100 1.19 2.23 3.09 3.85
110 1.26 2.34 3.22 4.00
20 1.32 2.44 3.34 4.14
5 standard 0.258 wall thickness 80 1.20 2.19 3.00 3.72
100 1.34 2.39 3.25 4.00
110 1.41 2.49 3.37 4.14
120 1.47 2.58 3.49 4.28
4 double extra strong 0.674 wall thickness 80 0.80 1.75 2.56 3.28
100 0.95 1.99 2.85 3.62
110 1.02 2.10 2.99 3.78
120 1.09 2.20 3.12 3.93
4 extra strong 0.337 wall thickness 80 1.12 2.11 2.93 3.65
100 1.26 2.32 3.19 3.95
110 1.33 2.42 3.31 4.09
120 1.40 2.52 3.43 4.23
4 standard 0.237 wall thickness 80 1.26 2.25 3.07 3.79
100 1.40 2.45 3.31 4.07
110 1.46 2.55 3.43 4.21
120 1.53 2.64 3.54 4.34
For SI: 1 inch = 25.4 mm, 1 pound per cubic feet = 16.02 kg/m3.
Note: Tabulated values assume 1-inch air gap between masonry and steel section.
FIGURE 722.5.1(5)
WIDE FLANGE STRUCTURAL STEEL COLUMNS WITH SPRAYED FIRE-RESISTANT MATERIALS
 
TABLE 722.5.1(6)
FIRE RESISTANCE OF CLAY MASONRY PROTECTED STEEL COLUMNS
COLUMN SIZE CLAY MASONRY DENSITY, POUNDS PER CUBIC FOOT MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CLAY MASONRY PROTECTION ASSEMBLY, Te (inches) COLUMN SIZE CLAY MASONRY DENSITY, POUNDS PER CUBIC FOOT MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CLAY MASONRY PROTECTION ASSEMBLY,Te (inches)
1 hour 2 hours 3 hours 4 hours 1 hour 2 hours 3 hours 4 hours
W14 × 82 120 1.23 2.42 3.41 4.29 W10 × 68 120 1.27 2.46 3.26 4.35
130 1.40 2.70 3.78 4.74 130 1.44 2.75 3.83 4.80
W14 × 68 120 1.34 2.54 3.54 4.43 W10 × 54 120 1.40 2.61 3.62 4.51
130 1.51 2.82 3.91 4.87 130 1.58 2.89 3.98 4.95
W14 × 53 120 1.43 2.65 3.65 4.54 W10 × 45 120 1.44 2.66 3.67 4.57
130 1.61 2.93 4.02 4.98 130 1.62 2.95 4.04 5.01
W14 × 43 120 1.54 2.76 3.77 4.66 W10 × 33 120 1.59 2.82 3.84 4.73
130 1.72 3.04 4.13 5.09 130 1.77 3.10 4.20 5.13
W12 × 72 120 1.32 2.52 3.51 4.40 W8 × 40 120 1.47 2.70 3.71 4.61
130 1.50 2.80 3.88 4.84 130 1.65 2.98 4.08 5.04
W12 × 58 120 1.40 2.61 3.61 4.50 W8 × 31 120 1.59 2.82 3.84 4.73
130 1.57 2.89 3.98 4.94 130 1.77 3.10 4.20 5.17
W12 × 50 120 1.43 2.65 3.66 4.55 W8 × 24 120 1.66 2.90 3.92 4.82
130 1.61 2.93 4.02 4.99 130 1.84 3.18 4.28 5.25
W12 × 40 120 1.54 2.77 3.78 4.67 W8 × 18 120 1.75 3.00 4.01 4.91
130 1.72 3.05 4.14 5.10 130 1.93 3.27 4.37 5.34
STEEL TUBING STEEL PIPE
NOMINAL TUBE SIZE (inches) CLAY MASONRY DENSITY, POUNDS PER CUBIC FOOT MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CLAY MASONRY PROTECTION ASSEMBLY, Te (inches) NOMINAL PIPE SIZE (inches) CLAY MASONRY DENSITY, POUNDS PER CUBIC FOOT MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CLAY MASONRY PROTECTION ASSEMBLY, Te (inches)
1 hour 2 hours 3 hours 4 hours 1 hour 2 hours 3 hours 4 hours
4 × 4 × 1/2 wall thickness 120 1.44 2.72 3.76 4.68 4 double extra strong 0.674 wall thickness 120 1.26 2.55 3.60 4.52
130 1.62 3.00 4.12 5.11 130 1.42 2.82 3.96 4.95
4 × 4 × 3/8 wall thickness 120 1.56 2.84 3.88 4.78 4 extra strong 0.337 wall thickness 120 1.60 2.89 3.92 4.83
130 1.74 3.12 4.23 5.21 130 1.77 3.16 4.28 5.25
4 × 4 × 1/4 wall thickness 120 1.72 2.99 4.02 4.92 4 standard 0.237 wall thickness 120 1.74 3.02 4.05 4.95
130 1.89 3.26 4.37 5.34 130 1.92 3.29 4.40 5.37
6 × 6 × 1/2 wall thickness 120 1.33 2.58 3.62 4.52 5 double extra strong 0.750 wall thickness 120 1.17 2.44 3.48 4.40
130 1.50 2.86 3.98 4.96 130 1.33 2.72 3.84 4.83
6 × 6 × 3/8 wall thickness 120 1.48 2.74 3.76 4.67 5 extra strong 0.375 wall thickness 120 1.55 2.82 3.85 4.76
130 1.65 3.01 4.13 5.10 130 1.72 3.09 4.21 5.18
6 × 6 × 1/4 wall thickness 120 1.66 2.91 3.94 4.84 5 standard 0.258 wall thickness 120 1.71 2.97 4.00 4.90
130 1.83 3.19 4.30 5.27 130 1.88 3.24 4.35 5.32
8 × 8 × 1/2 wall thickness 120 1.27 2.50 3.52 4.42 6 double extra strong 0.864 wall thickness 120 1.04 2.28 3.32 4.23
130 1.44 2.78 3.89 4.86 130 1.19 2.60 3.68 4.67
8 × 8 × 3/8 wall thickness 120 1.43 2.67 3.69 4.59 6 extra strong 0.432 wall thickness 120 1.45 2.71 3.75 4.65
130 1.60 2.95 4.05 5.02 130 1.62 2.99 4.10 5.08
8 × 8 × 1/4 wall thickness 120 1.62 2.87 3.89 4.78 6 standard 0.280 wall thickness 120 1.65 2.91 3.94 4.84
130 1.79 3.14 4.24 5.21 130 1.82 3.19 4.30 5.27
For SI: 1 inch = 25.4 mm, 1 pound per cubic foot = 16.02 kg/m3.
  1. Where the inside perimeter of the concrete protection is not square, L shall be taken as the average of L1 and L2. Where the thickness of concrete cover is not constant, h shall be taken of the average of h1 and h2.
  2. Joints shall be protected with not less than a 1-inch thickness of ceramic fiber blanket but in no case less than one-half the thickness of the column cover (see Section 722.2.1.3).
FIGURE 722.5.1(6)
CONCRETE PROTECTED STRUCTURAL STEEL COLUMNSa, b
 
TABLE 722.5.1(7)
MINIMUM COVER (inch) FOR STEEL COLUMNS ENCASED IN NORMAL-WEIGHT CONCRETEa[Figure 722.5.1(6)(c)]
STRUCTURAL SHAPE FIRE-RESISTANCE RATING (hours)
1 11/2 2 3 4
W14 × 233 1 1 1 11/2 2
× 176 21/2
× 132 2
× 90 11/2
× 61 3
× 48 11/2 21/2
× 43
W12 × 152 1 1 1 2 21/2
× 96
× 65 11/2 11/2 3
× 50 21/2
× 40
W10 × 88 1 11/2 11/2 2 3
× 49 1 21/2
× 45
× 39 31/2
× 33 2
W8 × 67 1 1 11/2 21/2 3
× 58
× 48 11/2 31/2
× 31 2 3
× 21
× l8 4
W6 × 25 1 11/2 2 3 31/2
× 20 2 21/2 4
× 16 31/2
× 15 11/2
× 9
For SI: 1 inch = 25.4 mm.
  1. The tabulated thicknesses are based on the assumed properties of normal-weight concrete given in Table 722.5.1(2).
For SI: 1 inch = 25.4 mm.
d = Depth of a wide flange column, outside diameter of pipe column, or outside dimension of structural tubing column (inches).
tweb = Thickness of web of wide flange column (inches).
w = Width of flange of wide-flange column (inches).
FIGURE 722.5.1(7)
CONCRETE OR CLAY MASONRY PROTECTED STRUCTURAL STEEL COLUMNS
 
TABLE 722.5.1(8)
MINIMUM COVER (inch) FOR STEEL COLUMNS ENCASED IN STRUCTURAL LIGHTWEIGHT CONCRETEa [FIGURE 722.5.1(6)(c)]
STRUCTURAL SHAPE FIRE-RESISTANCE RATING (HOURS)
1 11/2 2 3 4
W14 × 233 1 1 1 1 11/2
× 193 11/2
× 74 2
× 61 21/2
× 43 11/2 2
W12 × 65 1 1 1 11/2 2
× 53 2 21/2
× 40 11/2
W10 × 112 1 1 1 11/2 2
× 88
× 60 2 21/2
× 33 11/2
W8 × 35 1 1 11/2 2 21/2
× 28 3
× 24 21/2
× 18 11/2
For SI: 1 inch = 25.4 mm.
  1. The tabulated thicknesses are based on the assumed properties of structural lightweight concrete given in Table 722.5.1(2).
MINIMUM COVER (inch) FOR STEEL COLUMNS IN NORMAL-WEIGHT PRECAST COVERSa [FIGURE 722.5.1 (6)(a)]
STRUCTURAL SHAPE FIRE-RESISTANCE RATING (hours)
1 11/2 2 3 4
W14 × 233 11/2 11/2 11/2 21/2 3
× 211 31/2
× 176 2
× 145 3
× 109 2 21/2
× 99 4
× 61 31/2
× 43 41/2
W12 × 190 11/2 11/2 11/2 21/2 31/2
× 152 2
× 120 3 4
× 96
× 87 2 21/2 31/2
× 58 41/2
× 40
W10 × 112 11/2 11/2 2 3 31/2
× 88 4
× 77 2 21/2
× 54 31/2
× 33 41/2
W8 × 67 11/2 11/2 2 3 4
× 58 2 21/2 31/2
× 48
× 28 41/2
× 21 21/2 3
× 18 4
W6 × 25 11/2 2 21/2 31/2 41/2
× 20 21/2 3
× 16 4
× 12 2
× 9 5
For SI: 1 inch = 25.4 mm.
  1. The tabulated thicknesses are based on the assumed properties of normal-weight concrete given in Table 722.5.1(2).
MINIMUM COVER (inch) FOR STEEL COLUMNS IN STRUCTURAL LIGHTWEIGHT PRECAST COVERSa [FIGURE 722.5.1 (6)(a)]
STRUCTURAL SHAPE FIRE-RESISTANCE RATING (hours)
1 11/2 2 3 4
W14 × 233 11/2 11/2 11/2 2 21/2
× 176 3
× 145 21/2
× 132
× 109
× 99 2
× 68 31/2
× 43 3
W12 × 190 11/2 11/2 11/2 2 21/2
× 152
× 136 3
× 106 21/2
× 96 31/2
× 87
× 65 2
× 40 3
W10 × 112 11/2 11/2 11/2 2 3
× 100 21/2
× 88
× 77 2 31/2
× 60
× 39 3
× 33 2
W8 × 67 11/2 11/2 11/2 21/2 3
× 48 2 3 31/2
× 35
× 28 2
× 18 21/2 4
W6 × 25 11/2 2 2 3 31/2
× 15 21/2 4
× 9 31/2
For SI: 1 inch = 25.4 mm.
  1. The tabulated thicknesses are based on the assumed properties of structural lightweight concrete given in Table 722.5.1(2).
See More

Related Code Sections

722.5.1 Fire and Smoke Protection Features, Structural Steel Columns
The fire-resistance ratings of structural steel columns shall be based on the size of the element and the type of protection provided in accordance ...
722.5.1 Fire and Smoke Protection Features, Structural Steel Columns
The fire-resistance ratings of structural steel columns shall be based on the size of the element and the type of protection provided in accordance ...
722.5.1.1 Fire and Smoke Protection Features, General
and, the weight, W, and heated perimeter, D, of structural steel columns. As used in these sections, W is the average weight of a structural steel ...
722.5.1.1 Fire and Smoke Protection Features, General
and, the weight, W, and heated perimeter, D, of structural steel columns. As used in these sections, W is the average weight of a structural steel ...