Open Joist 2000 wood floor framing system

[PSUengineer1]

I have an Open Joist 2000 floor framing system. The joists are parallel chord trusses, consisting of solid-sawn lumber top and bottom chords and diagonal and vertical wood web members. Each end of the web members is finger-jointed into the top and bottom chords and glued with an adhesive.

The designation on the joist detail sheet is: 11-7/8UNin 4x2 SPF 2100F 1.8E 23’

What does the UNin mean?
What does the 4x2 mean?
What does 2100F mean? I think this is allowable bending stress, but not sure what the F means.
1.8E is modulus from my understanding.
11 7/8 is member overall depth.

Any help with the aforementioned designation (specifally, decoding it) is greatly appreciated.

Thanks,

 

[pmtpemb]

dont know about the un
4 x 2 is a 2 x 4 on the flat
2100f is the bending stress fb
1.8e is the mod of elast
11 7/8 overall joist depth.

 

[XR250]

Google is your my friend

http://www.openjoist.com/contact.html

dennis@alleghenystructural.com