I am going to be sprucing up my basement for use as a workshop and excercise area. I do not want to do a complete finished basement just redo the floor and ceiling. I have a couple of problems/questions that I need help with. My foundation is made of large stones, all shapes and sizes. The house is about 90yrs old. The problem is the concrete between the stones is crumbling. The walls seem to be structually sound and I have never had any problem with moisture of any kind in the basement. It is very dry. I think the original cement was a bad mix or had too much sand in it. I have already cleaned half of the basement and from the floor alone removed about 4- 5 gallon buckets of cement dust. I have not even swept out the joints to remove the rest of the loose stuff. Some places have been repointed by the previous owners. I need to do the rest. Any advice on how to do this the right way and prevent this from happening again? I want to take care of this rather than just put up walls in front of it only to have to address the problem in the future.

This is the closest forum I could find for this question. Please let me know if there's a better place to look. My home is built on a crawlspace, which is poorly ventilated at one end. When we bought the home, my home inspector told me that the living room/dining room is over the poorly ventilated end of the crawlspace, and as such, some of my floor joists are sagging a bit due to moisture. This is evidenced by a couple of small cracks in the drywall at the upper corners of a couple of door frames. The cracks have not grown in the 9 months we've lived there. The question is this. The home inspector said that it's a fairly simple process to stabilize things. He said I should just get a long 4x4 plank, three jacks and three concrete blocks. I should set the jacks on the concrete blocks in the crawlspace, with the 4x4 running perpindicular to the floor joists. He didn't suggest trying to jack the floor up, but simply stabilizing the floor. My question - is it really this simple - is this really something I could do myself reasonably?