Fire resistance is based on two test standards.
Ul class a roofing system.
To achieve a class a rating the roof must be effective against severe fire exposure.
Due to the materials used in their construction most asphalt shingle roof assemblies have a class a fire resistance rating.
The details for the manufacturers system typically include the following information.
It also serves as a key differentiator for products within the roofing market.
Class a roof assemblies are those that are effective against severe fire test exposure.
15 32 thick wood structural panels min.
Grade c d or sheathing.
There are three levels of fire resistance.
Experience maximum flame spread of 6 feet.
Class a roof assemblies and roof coverings shall be listed and identified as class a by an approved testing agency.
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.
Any ul class a b or c roofing system tgfu or prepared roof covering tfwz layer 2 roof sheathing.
Class a is the highest level.
Class a designates resistance to relatively severe fire test exposure.
Class a roof assemblies shall be permitted for use in buildings or structures of all types of construction.
The ul 790 classification e g.
It is not limited to thickness or incline restrictions like most foam roofing systems.
Class b designates resistance to relatively moderate fire test.
This is proven if it can.
A roof is classified as a class a as the result of one test the external spread of flame test astme 108 or ul 790 standard.
Ul class a industrial roof system.
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.
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.
This system is classified for all types of roof deck construction for fire resistive construction methods.
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.