I have a situation where the floor

[FK22]

I have a situation where the floor joist only attach to one side of a steel beam, is this going to cause problems with twisting? The floor joists are trusses and both the beam and the trusses are 16" high. The beam is 16" 40lbs per foot and is 30' long with a second floor exterior wall resting on it. Thank You

 

[KootK]

It's an issue but, generally, a resolvable one. We'll be able to offer greatly improved advice if you supply:

1) a sketch of the truss to beam connection detail.

2) a sketch of the beam to beam support connection detail.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[jayrod12]

Also provide truss spans and design loads.

 

[FK22]

THE PIC SHOULD BE ATTACHED
THANKS

 

[jayrod12]

What kind of connection is proposed between the screw jacks and the steel beam? To be honest, there's going to be a fair bit of torsion and not a ton of hope of resolving it if it's just sitting on a pair of screw jacks. What the actual intended connection between the truss and beam.

 

[FK22]

Was going to use strong-tie bracket, the wood is going to be bolted to the Web of the beam.
I can change the post to what ever will work.

 

[JAE]

is this going to cause problems with twisting?

Yes - a Simpson hanger attached to the side of a beam will twist the beam.
If the hanger is an over-the-top type hanger (top flange hanger vs. a face mount) it will twist the beam.
The wall on top of the beam, assuming a simple stud wall, will not help (much).
The beam will twist.
The screw jack columns, with a simple bracket top plate will not be capable of resisting the beam twist.
Find a local engineer to design this if you aren't one.

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[KootK]

Here are a few options to help mitigate the torsion problem. My preference would be A + D. That's simple enough that somebody might actually do it as specified. You contractor will, of course, object to the lack of field adjustability in the HSS.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[FK22]

Is the 16" beam overkill? The length is 25 ft. carrying the 16' floor trusses and 2ND floor and roof. Northeast USA.

 

[gwynn]

Is the bolted connection between the truss and beam enough that you have moment fixity between the two for the offset from centreline of beam to end of truss?? If so, if you take the truss as simply supported to the centreline of the beam, what is the rotation in the truss at the centreline of beam? The beam is not going to rotate further than the truss would if this was a pure pin situation. If the connection can handle the moment generated by the offset between the end of the truss and centreline of beam, and the rotations are small, I don't see a need to change the connection. Just make sure the screw jack can handle loads being applied off centre.

 

[dik]

Koot's A detail may help mitigate any cold transfer issues if this is an exterior wall support.

Dik

 

[jayrod12]

Detail A is my go to detail when supporting parallel chord wood trusses on steel beams.

 

[FK22]

Detail A looks good to me also, the only problem is the beam size is the same as the truss. Do I really need a 16" beam or can I use a shorter, heavier beam?

Thank you all!!

 

[SLTA]

FK22, the beam size should be a simple structural analysis, including torsion etc.

Please remember: we're not all guys!

 

[FK22]

is there a program to figure the beam?

 

[JAE]

Find a local engineer to design this if you aren't one.

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