a lot of homes these days, builders put gaps between every 4th brick or so. I believe they are called control joints right? something that was done on purpose.
anyways, to make a long story short, my father, not knowing what it is, and thinking that the builders did a poor job in building our home, voluntarily put slabs of cement to cover the gaps.
When I found out, I immediately knocked a lot of the cement out. I wasn't able to clean it 100% though. As a lot of the cement was already hardened, are there any tools I can use to clean out all the cement? using a hammer is kind of hard and I also dont want to crack the bricks.