## How far can wood joists span?

Floor joist span is the length of an individual joist, from the foundation walls to an interior beam. The spacing between joists is typically 16”, but can also be 12”, 20”, and 24”. The spacing and ability to span a greater – or smaller – distance is dependent on the size of lumber used for the joists.

**How far can joists span without support?**

But first, generally, how far can a 2×8 span without support? Depending on various factors, the maximum span for a 2×8 floor joist is 16′ 6”. The maximum span for roof rafters is 23′ 9”. For headers, the maximum span is 11′ 2”.

### How long can a timber beam span?

Changing to 600mm centres will change the span distances for the same timber sizes.

Joist size (mm) | Max span (metres) | |
---|---|---|

C16 | C24 | |

47 x 95 | 1.47 | 1.70 |

38 x 220 | 3.54 | 3.95 |

47 x 220 | 3.81 | 4.25 |

**What is the largest span all wood I joists are available for?**

IRC covers the maximum span length of wood joists, from 2×6 to 2×12 or greater. IRC also specifies floor joist sizing and spans depending on the joist spacing, commonly 16 inches on center but can vary from 12 to 24 inches apart.

## What size beam do I need for a 14 foot span?

Thus, for a 14 foot span, you will need atleast 3-2×12 or 6×12 size of wood beam. For a 14-foot spans, the wood beam has to be at least 12 inches in depth and 6″ in width (3-2×12) used for residential building, wood frame structure or projects.

**What joist can span 20 feet?**

What size i joist to span 20′:- as per general thumb rules and guideline, a 2-5/16″×11-7/8″ size of i joists made of engineered wood can allows spans up to 20 feet for a live load of 40 pounds per square foot and dead load of 10 pounds per square foot when spaced 16 inches apart.