Old Chicago Home Offset Deflection Wall Steel Beam 1

[citytreker]

I am working on a chicago home that has a steel beam running down the center of the basement with wood 2x10 joist floor framing clear span 24'. On the first floor there is a 2x4 deflection wall that runs parallel with the steel beam below - with the wall being offset 8.5" O.C. from the steel beam (6" flange, 6" deep).

I am creating an opening of 10' in the deflection wall and will use a LVL(s), however, now doubling up 2x4s for columns on either side of the beam will leave a point load that is offset from the beam.

Does anyone have a good detail or idea for this?

Thanks

 

[msquared48]

Your question can be answered here with any sketches. Can you upload one and post a URL to it?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[Lion06]

What is a deflection wall?

 

[hokie66]

To me, a "deflection wall" is a non-bearing wall which is braced laterally at the top, but is free to deflect relative to the structure above. If that is the case, I don't know why removing part of the wall would add loading to the supporting floor.

By the way, 24' is a long way for 2x10's to span. That would be a deflection issue.

 

[beton1]

Is the beam 24 ft long or do the joists span across (creating a 24 ft 'open' area basement)? Something doesn't seem right!?... as Hokie states. Likely the joists span 12 ft? The beam must have some supports if it is 24 ft long, otherwise a "6 x 6" W section would deflect, and there would definitely be strength issues. Typically the houses would have one or two posts in similar cases. Regarding your question, if there are point loads, you will need to reinforce/double up joists below; the beam may require stiffeners, depending on load. Clarify situation please. If it is a non-load bearing partition, what is the issue?

 

[citytreker]

Clarification: I am uploading a sketch.

I say deflection wall to mean a wall that is under joists which spans past the top of the "deflection" wall - yes it is a bearing wall (because 2x10 spanning 24' would not work), but there is no connection. This is typical old home chicago construction - most joists even 2x8's run clear span 20'-23' with intermediate walls that are offset from the basement beam.

The 2x10 run east-west at the 1st and 2nd floor. The beam runs north south under the first floor.

The walls are an exisitng condition. There was openings in the wall for a doorway. I am expanding the opening of the doorway from 3' to 10'.

http://files.engineering.com/getfil...a6f9-ab9f2fd80193&file=sketch_offset_wall.pdf

Thanks

 

[msquared48]

Looks like you are shoeing the "deflection wall" as you term it to be a bearing wall. In tht case, you will need to calculate the reaction at each end of the LVL and transfer that to thte 2X10's below. You will need to add additional structure in the plane of the 2X10s to taqke the aditional load, either sistering on new 2X10's or adding additional beams.

By the way, I agree too that a 24 foot clear span for 2X10's is excessive.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[msquared48]

A further note, If the steel beam is supporting the 2X10's at or near the center of the 24 foot length, then the joists are not overspanned. They should be checked for the new point load though as I mentioned.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask