Connecting metal joist to existing wall

[Ivan_Scal]

Can I use a seat angle on the bottom flange of my joist to avoid a differential settlement?

 

[jimstructures]

Normally the bearing angle mounts to the wall under the top chord of the joist. I imagine that many have been done the other way, i.e. under the bottom chord, WITH PROPER DESIGN.

Jim

 

[Ivan_Scal]

Hi Jim, thank you for your reply. My main concern is a differential settlement. I wonder which type of shear connection can prevent it.

 

[jayrod12]

None. The settlement would be of the supporting structure. The connection of the joist to the wall is only a concern for strength. Settlement is a different animal altogether and would have more to do with what is below the wall you're connecting to.

 

[Ivan_Scal]

That makes sense, thanks! I'm deciding between 4 shear connections. Which one would allow more independent movement? See attached.

 

[jayrod12]

Why do you want independent movement?

If these are steel joists, a single angle on the bottom will work but only if they are top chord bearing. If not, you'd also need a clip at the top of the joist to prevent rollover. I wouldn't do bottom chord bearing open web steel joists unless absolutely necessary. That's not how they want to fabricate them.

If the joists are expected to brace the wall for out of plane loads, then the top left one is no good. The bottom left one shows vertical slots, so that's useless for gravity loads. It would be one of the two on the right and depends on top or bottom chord bearing.