I recently visited a brick walled warehouse in Los Angeles built I think in
the 1960s. There was a brick haunch below the roof framing (a bow-truss wood
system), which was confusing to me. There was a pier below every truss
bearing point, and a brick wall which extended above the roof to a low
parapet. Apparently, they laid three courses of red 8" (?) brick on top of a
4" (?) brick wall, just below the roof connection. There is a wood sill plate
on top of this haunch. Perhaps it is used to transfer roof shear into the
wall by means of anchor bolts.
I would have imagined that they would have run the wall straight up to the
parapet and used a bolted ledger system to connect the roof and wall. Is it
possible that this brick haunch has some steel reinforcing embedded in it and
acts as a diaphragm chord / tie? I am pretty sure that it is not encasing
anything such as a rolled steel member as it appears to be full thickness.
The owner is planning to remove the ceiling framing and insert mezzanines.
These to not involve changes to the shell or its connections, but I would
like to recommend changes which will improve the safety of the structure. I
know that this type of building is succeptible to damage from roof to wall
connections. This is why I am concerned with the haunch system. Does anyone
have any experience with this system?