Thirty years ago, specifiers of low slope commercial roof systems only real choices were asphalt or coal tar built up roofs. As the roofing industry has evolved, there are many choices that are now available. Research the wants and needs of the building owner to determine which roof system is best for their building. Contact manufacturers to answer questions, inspect unusual details, make recommendations and supply job specific specifications and detail drawings. Insist on manufacturer inspections during the job to make sure their materials are installed properly. If proper specifications are written, quality materials are installed by a reputable contractor and in progress inspections are performed, most of you roofing problems can be avoided.