I've got three brick structures with adjoining walls. At some point in the last 110 years, an unknown joker decided that he wanted to add a couple of doorways through the common walls. Rough holes were knocked though the walls never being properly braced or supported. Amazingly, there aren't yet any stress cracks or related structural damage but I don't care to press my luck.
The walls are 12" thick and approx 3' wide. I'm guessing that I need to just knock a few more bricks out across the top and add some horizontal wood supports. My question is what type of wood is appropriate here. I'm sure that the typical HD 2x12 pine plank is totally insufficient for that type of load. Any thoughts?
-BB