Despite the recent popularity and widely touted benefits of vegetative roof systems, there still is some trepidation regarding the use of such systems among many in the construction industry. The concerns are not unfounded given a building's first line of defense against the elements is its roof.
In his 1989 book Roofing: Design Criteria, Options, Selection, Robert D. Herbert wrote "over 50 percent of post-construction problems can be attributed to roofing or related systems" and "approximately 65 percent of all lawsuits brought against architects during one recent period originated with roofing problems."
Although these statistics are dated, the explanation Herbert gives for these phenomena during the 1980s, namely the introduction of a large number of new roofing technologies in a brief time period, may be analogous to the current situation facing vegetative roof systems.
Vegetative roof systems, though viable alternatives to traditional roof systems, face some obstacles to widespread acceptance.