CMU wall removal

[stiffener]

I observed an existing one story strip mall built in the 60's. The owner has an existing 24' wide by 100' long space and wants to expand into the neighboring 100' by 100' vacant space and in the process remove the common wall. The roof structure consists of metal deck over M12 beams evenly spaced spanning in the 24' direction. The M beams frame into W12-W16 beams spanning in the 100' direction with HSS columns evenly spaced 20' along the 100'. The W beams cantilever over the top of the HSS columns.

The wall in question to remove is an 8" CMU wall with unknown reinforcing. At the top of the wall, there is a similar beam and column structure as the other column lines with the CMU constructed as infill between the face of the columns and up to the underside of the beam flanges. So I know that the CMU wall is not supporting gravity loads but without original documentation, how can I tell if the CMU wall is not acting as lateral load resistance. Of course the owner wants to remove all of the walls, but I am reviewing options. Given the inherit design of all of the beam/column connections as moment resisting and another CMU wall on the other side of the current space, I am debating if the CMU wall was constructed just for fire barrier separation.

Thoughts? Thanks.

 

[JAE]

You would want to fully investigate the entire structure and understand what its lateral brace system is.

Without knowing well how the building is supposed to resist wind/seismic, I'd be careful about removing walls.
Are there any X-braced bays? Diagonal bracing, etc.?

Do you know what the roof deck is and its attachments to verify diaphragm capacity?