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Old Steel Joist

Old Steel Joist

Old Steel Joist

(OP)
I'm not sure if anyone has tried to use this yet, if you have please let us know

It appears as if the SJI is willing to help with the investigation of old steel joists. Apparently all you have to do is fill out their form and send in the information and they will try to figure out the capacity of the joists.

This may be useful to some.

http://steeljoist.org/joist-investigation-form

RE: Old Steel Joist

This looks very useful. Although in their form then don't mention some of the old odd shapes like SJ joists with a notched plate for chords.

RE: Old Steel Joist

I bought the book - use to be about $80

Well worth it - to me!!

RE: Old Steel Joist

I have both versions of the SJI compilations....worth the money.

RE: Old Steel Joist

(OP)
This is something different. You give the SJI some information and they will tell you the likely size of the joist.

RE: Old Steel Joist

I wonder if they will give you a new capacity of a joist if you put another support in the middle, whatever that could look like...

Mike McCann
MMC Engineering
http://mmcengineering.tripod.com

RE: Old Steel Joist

I have used this form and submitted it to SJI several times. It can be be helpful, but there are limitations.

SJI will not analyze the joists. They simply review the member sizes and compare them to a table they have of known common member sizes that are specific to certain SJI joist designations, then pick the smallest joist that commonly consited of those member sizes. They will also not share the table with you, for liability reasons.

For example, if you submit a form that for a 30" deep joist erected sometime in the 1990's with a 2.5" deep seat and a top chord consisting of (2)-L1.75x1.75x3/16, you might get a response back from SJI that says something like,

"The joist you have presented resembles an 30K7 if manufactured by an SJI member company. K-Series 1986-Present."

I have spoken to them about their methodology in making these "recommendations", and they explained that they simply compare the given member sizes to common member sizes used in SJI joist designations from the time period, and pick the smallest joist with that member size. They do not do any analysis. Presumably, if the joist you submit does not resemble an SJI joist in either configuration or member sizes, you would receive a response that said something like,

"The joist you have presented does not resemble any joist manufactured by an SJI member company."

It is important to realize the limitations of their "best guess" "recommendation. In order for it to be considered acceptably reliable, and useful, you need to compare their "best guess" with results of your own analysis and the existing loads to see if everything makes sense.

RE: Old Steel Joist

They also use to have a software program on their site that "could" be helpful at times.

My rec - buy the book and do your own ciphering...

RE: Old Steel Joist

They also have a space where you can input a joist tag number. I once did this, and received a field use shop drawing from a job built in the 1970s!

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