The highest fire resistance rating for roofing as per astm e 108.
Fire rating of roof systems.
The ratings relate to fire tests designed to determine how quickly fire can raise the temperature to unacceptable levels.
Underwriters laboratories has defined the ul 790 standard tests of roofing material fire resistance to external fire sources.
The most widely accepted standards for fire resistance in building materials are those of underwriters laboratories inc.
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.
Roofing systems must meet or exceed building codes and insurance requirements.
Class a class b class c or unrated.
This non profit organization founded in 1894 devotes to testing and to establishing of fire safety standards.
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.
Roofing systems are rated by realistic fire tests.
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.
Class a is the highest rating offering the highest resistance to fire and unrated is the worst.
Astm e108 defines fire test methods for roof coverings.
Your roof can have one of four fire ratings classifications.
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.
A class a roof is ideal for fire protection and may be required by your building codes depending on your place of residence.
The ratings are as follows.
Indicates roofing is able to withstand severe exposure to fire originating from sources outside the building.
These tests may be conducted at ul inc fm global or any other certified testing laboratory.
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.
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.
How are roofs rated.
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.
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.
