1950s slab on-grade single story house in Southeast Pennsylvania
From outside in: brick, cinder block (I believe mortared to the brick totaling maybe 8 inches), black asphalt-type barrier paper, 2x2 studs, then drywall. There are weep holes on the outside of the brick.
My question is about the ¼ inch space between the cinderblock and the drywall that vents into the attic. Can that space be sealed at the top with foam without problems (mold, brick spalling, etc)?