floor slab squeaking

huangyhg

floor slab squeaking??
i'll do my best to explain the situation.  i'd like to get some insight from anyone here that has seen anything similar.
the client is looking to purchase an older commercial building and renovate it into a building for a private college.  here are the details:
the building is constructed of with steel columns, steel girders, bar joists, concrete on form deck slab.  
there are control joints around the columns and over the girders.  
the building was modified in the 70's accomodate storage floor loads.  
during the modification bar joists were added between the extisting bar joists.  
the existing joist were 20" deep.  
the new joist are 16" deep.  
the form deck is not in contact with two of the bar joists. the deck sits approx 1/4" above the top of the joists.  
the form deck was not welded.
this problem only occurs at one column in the entire building.  when you walk from one side of the girder to the other, or step on the corner slab near the column there is a squeaking noise and the floor deflects approx. 1/8".  the joist have solid bearing on the girder,there doesn't  appear to be anything wrong with the joists.  i don't think there is any strength or safety issues but the noises defeinatly create a serviceabiliy issue.  any ideas would be greatly appreciated.  thanks.
install intermittent steel shims tight between joist and form deck where joists are not tight to deck. weld shims to joist and deck.
does this column extend up through the slab?  if so, the deck may not have been supported directly on the column, which could be solved by welding some angles to the column.