Fire Rating Of Roof Systems

A class a roof is ideal for fire protection and may be required by your building codes depending on your place of residence.

Fire rating of roof systems. Fire rated wall floor and ceiling assemblies provide the necessary fire and smoke barriers to create compartmentalization during a fire safeguarding against the spread of fire and smoke within a building or to and from a building. These tests may be conducted at ul inc fm global or any other certified testing laboratory. Astm e108 defines fire test methods for roof coverings. The ratings are as follows.

Class a is the highest rating offering the highest resistance to fire and unrated is the worst. As applied to elements of buildings the fire resistance rating classifies the ability of an assembly to confine and isolate fire within a zone comprised of fire resistance rated walls ceiling and floor assemblies. Roof insulation fire performance before the latest amendments to adb the key fire consideration for flat roofing was requirement b4 which covered the resistance to fire from the outside of a roof system where achieving f ac to bs476 3 in the past and now b roof t4 gave unrestricted distance to the boundary of the building. Your roof can have one of four fire ratings classifications.

The highest fire resistance rating for roofing as per astm e 108. How are roofs rated. Fires that originate outside of the structure itself. Fire ratings for roofs are classified as either class a class b class c or are unrated if a roof covering cannot meet the requirements for any of these classifications.

Our roof systems are rated by code for external fire resistance under deck exposure and time temperature resistance. The ratings relate to fire tests designed to determine how quickly fire can raise the temperature to unacceptable levels. Indicates roofing is able to withstand severe exposure to fire originating from sources outside the building. 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.

Roof covering packaging that encloses shingles or other roofing that have a fire rating will display the level of fire or wind resistance rating of the materials. Underwriters laboratories has defined the ul 790 standard tests of roofing material fire resistance to external fire sources. 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. We must emphasize however that individual roof components are not rated at all.

Roofing systems are rated by realistic fire tests. These assemblies need to meet fire and smoke safety and environmental sustainability requirements. 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. Roofing systems must meet or exceed building codes and insurance requirements.