Had initially positive meeting with the contractor, he shared information about the work and how it should be done. Hired him to lower my basement floor without underpinning. The contract agreement stipulated digging out 8" of soil, for the purpose of pouring gravel, and then concrete on top - the final goal was to lower the basement floor by close to 5-6" from the old one.
Was told that this should be possible without underpinning. In retrospect, any contractor agreeing to this type of work should perform an exploratory dig to find out the depth of the footing. This was not suggested, and was not done.
On day 1, I paid about 1/3 of the total cost of the job as a retainer deposit.
After the contractor broke up the concrete in the entire basement, he dug up about 1/4 of the surface area of the basement - only about 3" of soil was removed. Due to the depth of the footing, it became apparent that the finished floor could not sit lower than 2" from the old one. This was not sufficient, and was not the scope of the project.
The contractor also complained that he underestimated how much soil disposal would cost him and said I would have to pay additional money for that. This tells me he was not experienced in this type of work.
The contractor wanted to proceed with the job, eager to start pouring concrete floor on top of the soil (and not put any gravel). There was still dirt and broken up concrete in the rest of the basement. After 3 days of work, I decided to pause the job and get an opinion on underpinning. The contractor said he is not qualified to do underpinning and I would have to get someone else for that type of work.
At this point we decided to break off the contract, and I asked for a portion of the money back, as it was obvious there wasn't enough work performed for the money I paid. The contractor said he would calculate his costs and get back to me. Nothing came through. When I persisted, the contractor claimed I owed him more money. Still refused to provide any justification for his costs. Eventually he claimed I owed him money for half of the job, and that if I did not leave him alone, he would come after me for the full amount of the job plus other costs.
To top it off, he shoved a plastic bag from gravel through a small hole in the rain drainage pipe that blocked water drainage and was flooding the basement - finally got a reputable plumbing company to snake it and pulled out a nasty surprise. Take it for what it's worth.
The matter is now with the lawyer, but sharing my experience for anyone else considering this contractor.