[Chemist1961]

Doing a spring outside inspection on my 35 year old home I have noticed a continuous gap between my main floor brick and the flashing above which sits below and behind the second storey stucco.
Should I be sealing this with expansion foam,or other to eliminate a down draft behind the bricks, etc and stop the bugs from nesting and moisture seeping in.
To explain better I think I could reach in above the brick and wrap my fingers over the top the the wall behind.

 

[Bob Mariani]

This should not be sealed. A clear airspace must be maintained behind the brick to vent moisture. Brick and their joints are not waterproof. However your wall seems to not be completely correct. At the bottom weep holes are left between the brick joints but are filled with a screen to prevent bugs. These may get clogged with spider webs which is one reason your builder left these open. I would suggest leaving it alone.

 

[Chemist1961]

Thanks Bob,
I do have that space below, about every 4-5 bricks a vertical gap between bricks in the bottom row, no mortar. I just never noticed the gap above the bricks and the flashing sits high enough that I could poke my fingers in between. It is also surrounds the coldest 2nd floor bedroom in the house.
So to be clear, the flashing should be secure but the air space should be contiunous along the top of the brick ledge, below the flashing... not an air gap say every few feet?

 

[Bob Mariani]

Could you post a picture? The gap at a window ledge or floor transition is sealed with caulking, not left open. Only gaps needed is what you see at the lower level (usually about the third row up from the bottom) and every third brick is about right. It is moisture that is being removed by air flow, not a wet condition. If a gap exists above any brick, excessive moisture will get into the wall. Gaps are left so they can be caulked, since the wood wall and bricks move at very different rates and these joist would otherwise crack. A foam backer rod and caulking is used. Be sure to clean first and tool joint with a back of a spoon.

 

[Chemist1961]

I'll take a pic and post it later today. thanks