Every number here is a working estimate to check with your building authority. Whoever prints this page takes responsibility for what is in it.
Side by side
Species changes the span
Show a hint
Northern species 2x8s at 16 in read from the spruce pine fir column: 12 ft instead of 9 ft 11 in.
| Joist | Max span | Cantilever | Verdict |
|---|
An asterisk marks a span longer than joist stock is normally carried, so your yard may not have it.
Every number here is a working estimate. Check it with your building authority.Turn JavaScript on to work the lesson. The drawing shows how it starts.
The rule this lesson teaches
Each species group has its own span column, and the northern group is the weakest.