No, these are NOT standard SJI joists. Thanks guys for your efforts, but the standard SJI tables are of no help.
The designation is correct and I remember seeing tables of a particular manufacturer that used to make these to get an advantage over their competition that did not have these available. The capacities must be gotten out of the specific manufacturer's tables.
The year of the joists was 1969. I am thinking it might be Armco or Sheffield.
We have a Sheffield Open Web Steel Joists (Armco Steel) Catalog #1565 (1966). It does not list a 24DH11, but does list a 24LH11. So that manufacture can't be it.
We also have a Ceco Deep Shortspan Steel Joists Catalog A.I.A. File No. 16-A (1967). It does list a 24DH11. "DH" Series Joists are fabricated from hot-rolled high strength steel sections having a minimum yield point of 50,000 psi. The design of these joists are based on allowable stress in tension of 30,000 psi. Ceco "DH" Series Open-Web Steel Joists are designed in accordance with the "H" Series specifications of the Steel Joist Institute.
I also am looking at an odd joist designation from Armco. The building is supposed to have been built in 1976. The tag from the joist shows J116 32 DH 10 21, ARMCO STEEL CORP
I downloaded the Ceco manual but they do not go to 32DH.
The joists are 4-ft o.c., current design snow load is 100-psf and should have been that in '76. The joists span approx 29-ft. This is a school building and I have mechanical equipment additions at several different roof areas.
