Keyword | CPC | PCC | Volume | Score |
---|---|---|---|---|

what size beam for 20 foot span | 1.84 | 0.7 | 6794 | 46 |

For a 20 foot span, wood beam needs to be minimum 18 inches deep. If smaller, beam will sag ugly!

To calculate beam spans, multiply the length of the beam with the maximum load of the floor of the room in pounds, and use this result to arrive at the beam's maximum bending movement. Use this figure to calculate the beam span or section modulus.

For example, if you are using an LVL beam with two plies of 16 inches or three plies of 14 inches with the columns spaced 14 feet from one another, the maximum span size is 36 feet. This span size only applies to single floors; floors supporting additional stories or roofs require sturdier construction and use different LVL span size charts.

A rectangular wood beam is to be designed to support first floor joists only (no bearing walls or other loads). The beam is to be simply supported at each end on support walls (2x4s). Clear span between stud walls is 14 feet. Span length is then 14.3 feet.