Fire Rating Of Roof Systems

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.

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. Class a is the highest rating offering the highest resistance to fire and unrated is the worst. Indicates roofing is able to withstand severe exposure to fire originating from sources outside the building. The ratings are as follows.

This non profit organization founded in 1894 devotes to testing and to establishing of fire safety standards. Roofing systems are rated by realistic fire tests. These assemblies need to meet fire and smoke safety and environmental sustainability requirements. Your roof can have one of four fire ratings classifications.

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. Roofing systems must meet or exceed building codes and insurance requirements. The most widely accepted standards for fire resistance in building materials are those of underwriters laboratories inc. Our roof systems are rated by code for external fire resistance under deck exposure and time temperature resistance.

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. 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. 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. We must emphasize however that individual roof components are not rated at all.

These tests may be conducted at ul inc fm global or any other certified testing laboratory. Class a class b class c or unrated. Underwriters laboratories has defined the ul 790 standard tests of roofing material fire resistance to external fire sources. 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.

Astm e108 defines fire test methods for roof coverings. How are roofs rated. The highest fire resistance rating for roofing as per astm e 108. Fires that originate outside of the structure itself.