Because roofs perform so many critical building functions, it shouldn’t come as a surprise that many of the best sustainable roofing practices today are the result of failures and not successes. The kinds of failures that drive sustainable roofing frequently are massive in scale. Historic conflagrations such as the 1871 Chicago Fire taught us the importance of preventing the spread of fire from roof to roof, resulting in the well-known Class A, B and C fire classifications for roofing systems. Over the past century, other devastating fires have led to the development of hourly fire tests for roof assemblies that help prevent the spread of fire within a building and extend the escape time for occupants. Even as recently as 1953, we were still developing under-deck fire ratings such as the UL-1256 Steiner Tunnel and the FM 4450 Calorimeter due to the massive GM Hydramatic Fire in Livonia, Mich., where a 30-acre factory complex was completely engulfed in less than 20 minutes.

Severe weather events also have played a large role in the development of sustainable roofing standards. As an example, current standards for cool roofs can be attributed in no small part to severe heat waves and brownouts such as the Chicago Heat Wave of 1995. But perhaps the disasters triggered by hurricanes and similar severe storms have taught us the most about how sustainable buildings (and roofs) need to be designed. In 1992, Hurricane Andrew showed us that hurricane wind forces can be much more devastating than we had originally thought. As a result, wind design standards across the United States were bolstered, with minimum design wind speeds rising by 30 mph or more. And coastal jurisdictions such as Miami-Dade County went even further with the development of wind-borne debris standards and enhanced uplift design testing.