Ducts or Pipes through Steel Joists - Maximum Sizes
Maximum sizes of ducts or pipes through K series joists.
Maximum duct or pipe sizes through steel joists of K type:
| Joists Dept (in) | Duct or Pipe Size | ||
|---|---|---|---|
| Round (in) | Square (in) | Rectangular (in) | |
| 8 | 5 | 4 x 4 | 3 x 8 |
| 10 | 6 | 5 x 5 | 3 x 8 |
| 12 | 7 | 6 x 6 | 4 x 9 |
| 14 | 8 | 6 x 6 | 4 x 9 |
| 16 | 9 | 7 x 7 | 6×10 |
| 18 | 11 | 8 x 8 | 7 x 11 |
| 20 | 11 | 9 x 9 | 7 x 12 |
| 22 | 12 | 9 x 9 | 8 x 12 |
| 24 | 13 | 10×10 | 8 x 13 |
K series are common open web joists, standard sized for typical applications. K types span from 8’ to 60’ across with depths of 8” to 30”.
