"isolating" outside beam?

[kingnero]

Came accross a situation today to which I have no answer (but it's also not my field of expertise).
Anyone cares to comment for possible solutions?

Problems: wall rests on two beams (one for the inside wall, one for the outside wall).
Beams are partly outside the "warm envelope" of the building, and logically attract humidity as it's the coldest place in the building.
Currently humidity comes from a fresh-placed low-cement ratio concrete on which floortiles will be glued, yet the problem will continue to exist afterwards as well...

During construction of the addition:

detail:

Problem:
view from inside the old building towards the new addition:

from the addition, looking at the beams:

possible solutions?

 

[XR250]

No matter what you do, that is a really bad detail unless flashing and weep holes were added above the new concrete deck.
Brick is pretty transparent to driving rain and the moisture will enter the cavity. It will eventually end up at your beam.
This may not be causing your current issue but may be one in the future.
I would try the spray foam approach for now.