Roof Fire Rating

Tim Rudolph
1/31/2014
Hi, I am in California in a high fire area. I would like to make sure my house is safe from wild fires so meeting the current roofing requirements is my goal. The house was built in 2004. I have a ASC delta rib 2 36" wide thru fastened panel metal roof it is underlain with 30# felt an 5/8" OSB over wood trusses. The current code requires a Class A roof Assembly. In San Diego county attic ventilation is required to have special vents that prevent ember intrusion ( see 2 question on foam closures) 1. Is the 30 # felt the proper underlayment for the Assembly rating? 2. are the foam closure strips fire proof? how should the ribs be closed at the eaves to prevent embers from blowing under the metal panel and igniting the roof deck? 3. At the ridge the roof panels are a 1-2" inches short of the peak and covered with 30# felt. The ridge cap sufficiently overlaps the panels to make it weather proof. Is this ok for the Class A Assembly rating? how should it be fixed to comply with the class A rating? if needed I called the mfg and asked for guidance on the class A assembly and they pointed me to the building code. The CA code section fails to provide how to build a Class A Assembly only talks of the covering. Thanks for you help
Todd Miller
Classic Products, Inc.
1/31/2014
The code is in the process of changing. In the past, with steel roofing, the 30# felt would suffice. If they have adopted the new code in your municipality though fire rating will be as disctated by performance testing done on the actual roofing material you're installing. That would need to come from the roofing manufacturer. One option is to use VersaShield or Dens Deck as they have Class A ratings on their own for use in just about any roofing assembly. On your question 2, the foam closures are not fire rated. You may need to make metal closures. On number 3, if the ridge detail is appropriate per manufacturer instructions, you should be okay on the fire rating.

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