Existing Open Web Joist
Existing Open Web Joist
(OP)
I am trying to figure out the configuration of an existing joist. It does not seem to fit the configuration that would help me determine the proper designation as specified in the 75-year Steel Joist Manual. Does anyone have any other suggestions to determine the proper joist callout?
What I do know is:
• Building constructed in the 60s
• Depth = 16"
• Top chord = 2-L2x2x3/16
• Bottom Chord = 2-1x1x3/16
• Web = ½" diameter rods
From the construction year it appears to be a "J" or "H" joist, but there is a big difference not only in the J or H capacity, but also if it is a 16J_ or a 16H_.
Thanks for any additional information, and at worst I know I can take the minimum capacity of a 16" deep joist.
-D
What I do know is:
• Building constructed in the 60s
• Depth = 16"
• Top chord = 2-L2x2x3/16
• Bottom Chord = 2-1x1x3/16
• Web = ½" diameter rods
From the construction year it appears to be a "J" or "H" joist, but there is a big difference not only in the J or H capacity, but also if it is a 16J_ or a 16H_.
Thanks for any additional information, and at worst I know I can take the minimum capacity of a 16" deep joist.
-D
RE: Existing Open Web Joist
RE: Existing Open Web Joist
RE: Existing Open Web Joist
RE: Existing Open Web Joist
I've seen that said a few times here, but wish you would explain. Since it is a long time since I worked in the US, it is a long time since I have used bar joists. But I always thought they were designed and could be analyzed in the same way as any other truss, provided you know how.
RE: Existing Open Web Joist
As I recall, if you did the analysis as a strict truss, the numbers didn't work with the old tables. I've analyze them as deep beams,neglecting the web and gotten closer. Obviously parts of them have to be looked at like a truss, particularly when considering buckling of the first diagonal under load reversal.
Might be an exercise for a few beers and a boring night.
RE: Existing Open Web Joist
RE: Existing Open Web Joist
RE: Existing Open Web Joist
RE: Existing Open Web Joist
RE: Existing Open Web Joist