Ray Bradbury's classic novel Fahrenheit 451 is a commentary about free speech and censorship. In the novel, 451 F is identified as the temperature at which booksor paperwill ignite and censorship of the written word will be achieved.
Although not about roofing, the novel introduces a fundamental concept that can be applied to the fire safety of torch-applied polymer-modified bitumen roof systems. For example, if during the application process the ignition temperatures of combustible substrate materials are not reached, the likelihood of fire is greatly diminished.
To test this concept as it applies to torch-applied polymer-modified bitumen roofing products, NRCA and Hughes Associates Inc., Baltimore, a nationally recognized fire consulting firm, devised a program to test whether commonly encountered combustible substrates will likely ignite during torching; the test revealed the minimum ignition temperature of such substrates is 570 F.