There are many roof types, and every roof will wear differently relative to its age, the number of its layers, the quality of its material, the method of its application, its exposure to direct sunlight or other prevalent weather conditions, and the quality and regularity of its maintenance. Regardless of its design-life, every roof is only as good as the water proof membrane beneath it, which is concealed and cannot be examined without removing the roofing material, and this is equally true of most roofs. In fact, the material on the majority of pitched roofs is not designed to be waterproof only water-resistant. However, what remains true of all roofs is that, whereas their condition can be evaluated, it is virtually impossible for anyone to detect a leak except as it is occurring or by specific water tests, which are beyond the scope of the inspection and disclaimed. The inspector may walk the surface of a roof in order to inspect it and its components, but may inspect it by other means if the roof cannot be safely accessed, due to its height, weather conditions, or if the roofing material could be damaged by foot traffic.