Great contractors are like great architects.  They are wonderful to work with.  I remember one contractor I worked with that I did not even have to do a punch list (list of items which need more work) at the end of the job.  He was so detailed and so thorough! But while the majority of general contractors are trying to do a good job and build a good reputation, there are a few that we need to steer clear of at all costs or at least get a measure of protection by avoiding certain practices.  I have seen contractors trying to get as much money as possible up front by overcharging for items not installed in the initial phases of the work.  It is easier to AVOID a dispute with contractor than to try to fix a dispute once it starts.

• Hiring a contractor without checking him out thoroughly. References are necessary. Visiting several projects he has built is a good idea.
• Making the contractor angry at the very beginning of the project. Bills have to be paid on time. Cooperation with the contractor will establish the "tone" for the project and the project will run smoother. When I am hired to do jobsite meetings, I like to start the meeting with what went right that week on the job. This is an amazing tool to get the contractor's cooperation. All people like to be recognized for what they do right and not what they do wrong.
• Contractors with limited construction knowledge and experience. The contractor may not understand the plans and this could lead to mistakes in the project.
• Contractordemands and collectssubstantial amounts of money from the client prior to doing any work. I advise my clients never to give more than 10% of any contract for mobilization (to start the project).
• Changing any details, but especially structural details, without the prior consent of the architect/engineer. This could lead to a problem that is not visible in the present but could cause a problem in the future.
• Paying the contractor too much money with each pay request, leaving the client vulnerable to the contractor not finishing the job. The amount of work that is left could end up being more than the money that the contractor would collect, if he finished the job.
• Signing a contract with the contractorwhich the contractor drafted, that is not to any known standard, such as the ones published by the American Institute of Architects.
• Paying the contractor month after month without verifying that the required county/city inspections are getting done.
• The client pays all the money required by the contractor at each pay requisition, but fails to obtain Partial Releases of Liens from his subs, leaving the client vulnerable to having to pay each sub again, if the contractor runs off with the money.
• Hiring a contractor for a job that the contractor considers a "small" job for him or where the company is a large company with substantial resources to spend years in court fighting a lawsuit. Look for a company that is neither too large nor too small to complete the project and who will want to finish the project correctly.
• Not getting a final city/county inspection and not getting a final certificate of occupancy/ completion.
• Inadequate review of the pay request prior to payment to the contractor.