When making improvements to your home make sure you pay careful attention to whom you hire. How and when you pay, do they have a current and valid license/credentials to do the work, check references and make sure your GC has insurance.
You know the drill: they all want to get a huge down-payment from you upon signing of the contract. Is this necessary? If they haven't pull any permits or remove a brick from your house. Why do you have to pay 30% -50% upfront?
In most cases, the reason is simple: They do NOT have a working capital. Most of them are running behind in work they have already committed to previous customers, but they have spent the working capital given to them before finishing the job.
This is why the smallest payment required in most of their contracts ("draw" as they call it) comes at the very end. An when the job is around 80% finished, they call it quits ... walking out of a small final payment looks like a smart move if another huge "down-payment" is waiting across the street to start a new job doesn't it?
Choosing a Contractor is not easy .. and if you don't do your home work you can end up having to pay someone else to finish a job previously paid for.