Contractors

One reason why you should never pay a contractor as soon as the work is done is that it's only after 10 days you will find anythign wrong that needs changing.

A contractor that still wants to get paid is more likely to do the work quicker than one who hasn't recived their money.

I still think 50% - 50% is the best way to work.

50% at that start and 50% within 30 days of delivery.

This way the contractor knows you are serious. Has cash to keep them happy and the company still has soem control over work getting done in time and any unforseen changes.