Roofing Material Fire Ratings

Common underlying materials include a type 72 roll roofing material also known as 72 pound felt or 72 pound capsheet material and a panelized gypsum product called densdeck.

Roofing material fire ratings.

In a recent roofing column we focused upon technical information that could be found on roofing material wrappers that could verify compliance with various building codes. An exterior fire retardant treated shake roof has a stand alone class b rating. Understanding roof fire ratings class a roofing. Astm ul 790 tests for fire resistance of roof covering materials underwriters laboratories has defined the ul 790 standard tests of roofing material fire resistance to external fire sources.

The slope of the test specimen is preselected and since steeper slopes are more of a challenge due to melting material feeding the fire the rating applies to the maximum slope passed. Fires that originate outside of the structure itself. Wood shake plywood or particle board roof are the most common roofing types listed as class c. But by including a particular underlying material it can meet the requirements for a class a roof.

Class a does not mean grade a roofing systems are rated by realistic fire tests. Class c fire resistant roofing material. Ul 790 underwriters laboratories roof fire ratings a b c tests. This month let s take a closer look at one particular type fire ratings.