1970s Era Steel Joist Designation

[albanyYEM]

I am trying to analyze the capacity of an existing joist within a building of which the original construction drawings are dated January 1974.

The framing plan indicates "36H13". When I go to my 50 Year Steel Joist Digest by SJI, I find "H" joists in the May 1971 load tables but they only go to 24H designations and no deeper. Going back an iteration of the "H" load tables, they still go no deeper than 24".

The July 1970 LH series load tables list a "36LH13" which is not quite the same as the "36H13". I reviewed several of the documents on the Slide Rule Era webpage and still didn't see any "36Hx" members.

Soliciting opinions here on using the LH load table for an H series joist of the same general era for which I can't find a load table. Anyone run into this previously?

Thank you

 

[EngineeringEric]

Have you tried to contact SJI? Ken Charles is so helpful

I would say that the LH designation on your plans may have just been dropped to H, but who knows!

For Reference:
1929-1958 SJ-Series
1958-1961 S-Series
1961-1978 J-Series
1961-1986 H-Series
1986-Present K-Series

 

[JAE]

Yes perhaps an unknowing engineer who wasn't careful with their joist designations?



Check out Eng-Tips Forum's Policies here:
faq731-376

 

[Guastavino]

H-series were joists produced in the 70s. If you purchase the 75 year steel joist manual from SJI, it has all the load tables for that. It's pretty cheap to purchase and has a TON of invaluable knowledge.

I have a copy of the manual open that I purchased and I can see the tables. I'd post them, but I don't want any copyright infringement. Just know that SJI has them if you need them.

 

[JAE]

albanyYEM did say they had the SJI book.

Check out Eng-Tips Forum's Policies here:
faq731-376

 

[albanyYEM]

Yes, I have the 50 Year SJI book which says it covers 1928-1978. Seems like the information I'm seeking, if available, should be in this resource.

I will contact SJI regardless but if in the interest of time, someone might be kind enough to post the pertinent load table information for the following conditions I would greatly appreciate it:

36H12 56' span
36H13 56' span

Looking for whatever is listed, be it TL/LL, Max End Reaction, Max Resisting Moment, etc. Again, building drawings are dated January 1974.

I appreciate everyone's consideration. Thanks

 

[jdcollins]

The deepest "H" series joist I can find is from the 1972 and 1974 tables which added 26" to 30" inclusive, still no 36H joists. This is from the 60-Year Joist Manual.

The deepest and heaviest joist listed is the 30H11. I know it's not what you're looking for, but here's the info anyway:

For 30H11, 56' span -
Moment: 1,397,000 in-lbs
End Reac: 8700 lbs
Weight: 18.8 lbs/ft
TL: 297 plf
LL: 144 plf


Also, I just wanted to say that I'm really digging your forum username.

 

[albanyYEM]

Thanks jdcollins, we are everywhere!

I did hear back from Kenneth Charles at SJI who informed me that H series never went past 30". He suspects a mislabeled joist designation as others did here as well. Thank you for all the feedback. It's nice to have the ability to reach out like this. And even better that folks are willing to assist. Much appreciated.