This is a wall in the extension to my house, which I estimate to have been added around the 1930s (house is 1909) using mostly
large hollow bricks that look more like cinder blocks but are not of concrete and brick-like clay instead.
I need to plaster the exposed brick (there is a reason why I couldn't frame and drywall) and I was thinking, since these elements are hollow, does it make sense to drill a small hole in each and fill it with
insulation foam, to improve the house
R value. The only reason against I see is that the foam may expand if moisture comes from the outside (the other side of where I'm plastering) and explode the brick.