Legal Question in Construction Law in California

Re: Unfinished Job

First, check to see if he is licensed. If not, you owe him nothing. If he is licensed, it is possible that he materially breached the contract. Only a judge or jury can tell you whether a breach is "material". For the most part, a refusal to adequately man the job after several demands to do so is enough to rise to the level of material breach.

Your damages are the difference between the contract with the abandoning contractor and the cost of finishing the painting with another contractor. You can also likely hold him responsible for consequential damages.

You are entitled to withhold 150% of the amount in dispute. It can sometimes be difficult to determine the amount in dispute. In your case, this could be determined by the bid of the replacement contractor. For example, the bad contractor bid $10,000 to do the job, but the replacement contractor bids $9,000 to finish the work. The bad contractor claims that he's done $2000 worth of work. But, since it's going to cost you at least $1000 more to finish the job ($9000 plus $2000), then $1000 is in dispute so you're entitled to withhold $1500. Re-keying would be consequential damage, so could legitimately be added to the amount in dispute. Basically, consequential damages are any damages that would logically flow from the breach.