There are three levels of fire resistance.
Ul class a roofing system.
Class a roof assemblies and roof coverings shall be listed and identified as class a by an approved testing agency.
Grade c d or sheathing.
Fire resistance is based on two test standards.
15 32 thick wood structural panels min.
It is not limited to thickness or incline restrictions like most foam roofing systems.
This system is classified for all types of roof deck construction for fire resistive construction methods.
Class a designates resistance to relatively severe fire test exposure.
For fire tests of roof coverings and ul 790 standard test methods for fire tests of roof coverings the tests provide the basis for the class a b and c designations.
Class a roof assemblies shall be permitted for use in buildings or structures of all types of construction.
The details for the manufacturers system typically include the following information.
Any ul class a b or c roofing system tgfu or prepared roof covering tfwz layer 2 roof sheathing.
Class a roofing is the preferred choice for any home but this type of roofing is particularly important if you live in an area that is prone to wildfires.
Class a b or c the deck construction supporting the roofing system combustible or noncombustible any restrictions on the roof incline required or optional if so indicated barrier boards ply sheets and surfacing.
This is proven if it can.
Class b designates resistance to relatively moderate fire test.
Ul class a industrial roof system.
Certification database ul product iq access ul certification data on products components and systems identify alternatives and view ul guide information with product iq.
To achieve a class a rating the roof must be effective against severe fire exposure.
Class a is the highest level.
A class 1 roof has undergone a series of tests that evaluate the entire roof assembly including the external spread of flame test utilized for the class a rating.
The ul 790 classification e g.
Experience maximum flame spread of 6 feet.
Ul 790 and astm e 108.
Class a roof assemblies are those that are effective against severe fire test exposure.
Due to the materials used in their construction most asphalt shingle roof assemblies have a class a fire resistance rating.