Early Steel Bar Joists 1

[LPPE]

I've got a building built circa 1938, and has SJ81's for floor joists. Anyone know what the seat height may be on those? And what the top and bottom chords are? The chords look like rectangular steel bars on the flat from the 1 picture I have.

 

[JedClampett]

The Steel Joist Institute says for Chord Size "1", the top chords were commonly 3/4 x 3/4 x 1/8 or 1 x 1 x 1/8 angles and the bottom chord was the same or 3/8 round bars. They say however that other sizes might have been used and were perfectly adequate.
I got this from the SJI publication "Steel Joist Institute 60-year Manual"

 

[dik]

Short span joists of that ilk typically had a 2-1/2" deep joist seat.