PROPOSED CMU WALL ABOVE EXISTING CMU WALL WITH GIRT SANDWICH

[dylansdad]

I have an existing industrial building (pre-engineered metal building). Inside this building is proposed an enclosed interior space (with a lower ceiling/roof) adjacent to 2 exterior walls. The existing exterior wall is 8" cmu (#4@48")up to 7'-4" above finish floor. Constructing a new wall immediately adjacent and interior to the existing cmu would cause sprinkler/piping headaches and would be discontinuous at steel columns. Contractor has proposed the following (see sketch). I would propose to find the unreinforced cells, knockout the bottom (accessible from the exterior)and install reinforcing as needed. Drill existing purlins to allow reinforcing to pass through and continue with typical cmu wall construction. The channel at the top of the existing wall is bolted to the metal building columns. My concern is with the horizontal joint that would occur at the girt (don't know girt spacing). Have I thought this through enough or have any of you any concerns? Wind load is 90 mph, SDC=C. Thanks for any and all replies.

 

[hokie66]

I don't think either you or the contractor has thought it through. Just get rid of the cladding and girts, build your wall to the standard required, then reinstate cladding.

 

[ztengguy]

So the girt would still take the same wind load correct, your just adding some dead load to the footing. EQ would be the only other concern and making sure the girt can take that load. not sure if yo could do a composite type thing with the CMU and the girt, would have to think a bit more about that. You could weld some tabs to the girt to anchor to the CMU. Deflection would be the other thing too with the CMU

Can you span a beam column to column in the girt space to carry the new load, and do away with the CMU idea? Footing is the weak link then.

 

[dylansdad]

That was my first thought. Thanks Hokie.

 

[Teguci]

Remove the girts and brace the wall against the other new walls you will be building. Anchor the facade directly to the wall with new anchors.