Permissible Clear Spans for Ceiling Joists (to BS 5268-7.3)

Imposed load
0.25 kN/m²
Strength class
  • Find the column for your dead load and spacing, and the row for your timber size to find the permissible clear span in metres.
  • Click on a span to generate a full calculation (you can adjust the exact span).
  • This span table is to the format and methodology given in BS 5268-7.3.
  • These spans were calculated using our ceiling joist calculation engine.
  • These span tables are the equivalent of other industry-standard span tables and are calculated to the same standards.
  • This table uses commonly available UK regularised timber depths.
  • Read the notes at the bottom of the table for assumptions, references and related standards.
Back BACK CEILING JOIST CALCULATOR
C24
Dead load per square metre (in kN/m²) supported by joists
Not more than 0.25 More than 0.25 but not more than 0.5
Centre-to-centre spacing of joists (in mm)
Joist size
Width × depth (mm)
400 450 600 400 450 600
Permissible clear span (metres)
38 × 72 1.269 1.258 1.226 1.226 1.211 1.172
38 × 95 1.865 1.844 1.784 1.784 1.758 1.687
38 × 120 2.552 2.516 2.420 2.420 2.378 2.267
38 × 145 3.264 3.211 3.073 3.073 3.013 2.858
38 × 170 * 3.990 3.920 3.736 3.736 3.657 3.456
38 × 195 * 4.725 4.636 4.405 4.405 4.306 4.057
38 × 220 * 5.465 5.355 5.076 5.076 4.957 4.659
44 × 72 1.363 1.350 1.315 1.315 1.299 1.255
44 × 95 1.996 1.972 1.907 1.907 1.878 1.800
44 × 120 2.723 2.684 2.578 2.578 2.532 2.412
44 × 145 3.474 3.416 3.266 3.266 3.201 3.034
44 × 170 4.237 4.161 3.963 3.963 3.878 3.663
44 × 195 * 5.007 4.911 4.664 4.664 4.559 4.293
44 × 220 * 5.780 5.664 5.366 5.366 5.240 4.924
47 × 72 1.407 1.393 1.356 1.356 1.339 1.293
47 × 95 2.058 2.032 1.964 1.964 1.933 1.852
47 × 120 2.803 2.762 2.652 2.652 2.604 2.479
47 × 145 3.571 3.512 3.356 3.356 3.289 3.116
47 × 170 4.351 4.272 4.067 4.067 3.980 3.758
47 × 195 * 5.137 5.038 4.784 4.784 4.675 4.402
47 × 220 * 5.925 5.805 5.500 5.500 5.370 5.046
63 × 95 2.347 2.316 2.233 2.233 2.196 2.100
63 × 120 3.176 3.127 2.998 2.998 2.941 2.795
63 × 145 4.025 3.955 3.775 3.775 3.697 3.498
63 × 170 4.880 4.790 4.557 4.557 4.456 4.204
63 × 195 5.737 5.625 5.338 5.338 5.216 4.909
63 × 220 6.590 6.457 6.118 6.118 5.973 5.612
ALS/CLS
38 × 89 1.706 1.687 1.636 1.636 1.612 1.550
38 × 114 2.385 2.352 2.266 2.266 2.227 2.126
38 × 140 3.120 3.071 2.942 2.942 2.885 2.739
38 × 184 * 4.401 4.320 4.110 4.110 4.019 3.792
* Boarding to be fastened on top of ceiling joists with a depth to width ratio greater than 4