A General Contractor is the project manager for construction projects. A General Contractor who is not experienced in doing the construction work himself is at the mercy of any sub-contractors used on a project, particularly with regard to the materials and techniques used. While a General Contractor's name is on the work, sub-contractors are generally unknown to the client and have no vested interest in providing the best possible result for you. They want to finish the project as quickly as possible and get to their next job. If a General Contractor does not have experience knowing the proper way to do things he is unable to ensure the work is done correctly and risks an unhappy client.
A General Contractor is the project engineer or project manager for construction projects. While there are no set educational qualifications, a General Contractor generally starts out as a construction worker and learns about different aspects of construction, including masonry, carpentry, framing, and plumbing.
A general contractor is responsible for the day-to-day oversight of a construction site, management of vendors and trades and communication of information to involved parties throughout the course of a building project.