Originally Posted by notuseless
Would throwing chunks of brick in the empty space be a bad thing? As the bags of cement patch i've seen seem to be pretty small. I'm meaning just in the hollow of the cement block to give it a big of resistance.
I'm a General contracotor..
What you have there is a concrete poured over hollow block cores.
Remove all loose material on the side. Don't be afraid to tap with a hammer to check for areas that may give way later. The main prep objective is NO loose substraignt..
The first goal is to get some Mortar NOT concrete and lay in some chunks of block, brick, or even stones broken up. Mix mortar very Pasty like thick peanut butter. lay/mortar in those voids with chunks to produce a fairly flat vertical surface. Now that gets us to a solid sub-straight but its not "tight" enough to endure the weather. Use a this product :
Thoroseal Cement Based Waterproofing for Concrete
This will Waterproof the the whole side to protect the existing Concrete as well as the patch and give you a more finish off look.