Floor joist renovation. Discovered under 2 layers of laminate flooring that there was a concrete slab where the soapstone stove (smaller model) has stood and will stand in the future. However, the joist needs to be completely replaced as it is weak. Unfortunately, the concrete is cast into the joist and only there - meaning it doesn't reach down to the ground. I've tried chiseling it away with hand tools but it will take years. I don't quite dare to use a demolition hammer because the joist doesn't feel stable enough to handle the impacts. How should I proceed if I want to keep it? Considering building with leca from underneath... is that possible?! I can't reach to lay mortar on the last row - does that matter?! How much and in what way must I prepare the ground before building in that case?! Grateful for tips and thoughts.
