Old Steel Roof Joist Analysis
Old Steel Roof Joist Analysis
(OP)
I am having to analyze some old steel open web joists. I don't have the joist designation, unfortunately. From my research, I found out the building was constructed in 1946. I don't have the "80 Years of Open Web Steel Joist Construction" by SJI and I'm not sure the joists in question would be in there b/c they are a little odd. The web members are a mix of angles and flat steel (all diagonal web members are flat steel except the two outermost, while the vertical web members are angles). I've attached a rough sketch of the joist. Before I by the "80 years" book from SJI, I was wondering if anybody had any info on a joist like this or would know where to look for load tables, etc.
Thanks for any help, see attached sketch.
Thanks for any help, see attached sketch.






RE: Old Steel Roof Joist Analysis
If you don't have any means to identify the joist...I wouldn't count on any SJI table. What is the guarantee that the joist was originally designed per SJI specifications.
RE: Old Steel Roof Joist Analysis
More likely than not, these are ones that were designed and fabricated for that particular building. If so, you will have to do a computer analysis, but that should be simple enough.
There have been other manufacturers over the years like Macomber and Great West that are not documented in the SJI catalog. I could be wrong and this may be one of them, but de3finitely not GW or Macomber.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Old Steel Roof Joist Analysis
BA
RE: Old Steel Roof Joist Analysis
RE: Old Steel Roof Joist Analysis
RE: Old Steel Roof Joist Analysis
RE: Old Steel Roof Joist Analysis
RE: Old Steel Roof Joist Analysis
Alternatively, accurate deflection can easily by computed by hand as well.
BA