Roof Assembly Fire Class Criteria

Tested roof systems are fire classified class a b or c where the most fire resistant roof assemblies are class a and class c is least resistant.

Roof assembly fire class criteria.

1505 2 class a roof assemblies class a roof assemblies are those that are effective against severe fire test exposure. 1 an intermittent flame test in which the flame is turned on and off during the roof assembly to resist. Examples of a by assembly fire rating include fire retardant treated wooden shakes and aluminum roof coverings. 6 usg fire resistant assemblies test certification test conditions and fire and sound tested assemblies listed in this selector are based on characteristics properties and performance certificationof materials and systems obtained under controlled test conditions as set forth in the appropriate astm standard in effect at the time of test.

These listings are short summaries to serve as a. B or c roof assembly a class a b or c assembly cannot be. Roofing systems must meet or exceed building codes and insurance requirements. It should be noted that these classifications apply to roofing assemblies and not the roofing membrane.

Our roof systems are rated by code for external fire resistance under deck exposure and time temperature resistance. Class a does not mean grade a roofing systems are rated by realistic fire tests. A roofing membrane that is classified as part of a class a assembly when installed over a particular insulation may not qualify as part. Fire ratings may pertain to resistance to fire from above the roof system the familiar class a b or c ratings or fire exposure from the building interior the underside of the roof deck.

But by including a particular underlying material it can meet the requirements for a class a roof. Test conditions and pass criteria are shown in table 1. Class a roof assemblies shall be permitted for use in buildings or structures of all types of construction. We must emphasize however that individual roof components are not rated at all.

Roofing assembly classification will need to be for each roofing project. Class a roof assemblies are those that are effective against severe fire test exposure. Assembly rated class a roof coverings are those that meet class a standards when combined with other elements. Building code fire resistance requirements building codes establish fire resistance requirements for roofs based on the type of construction e g concrete steel wood for the building.

For roof assemblies with combustible decks wood plank t g astm e 108 and ul 790 require two additional fire tests. Class a roof assemblies and roof coverings shall be listed and identified as class a by an approved testing agency. Class a roof assemblies and roof coverings shall be listed and identified as class a by an approved testing agency.