Correct installation of a roof coating is only achieved when the selected product is installed over a properly prepared substrate with the correct equipment by a trained contractor. While each of these are equally important (product, preparation, equipment, contractor), the contractor is the key variable, and their training is paramount to the installation of a roof coating system. This becomes clear when one understands how a contractor’s level of skill and knowledge informs the decision-making process for the major aspects of a roof coating installation.