Rated Roof Assemblies

The ratings relate to fire tests designed to determine how quickly fire can raise the temperature to unacceptable levels.

Rated roof assemblies.

Over non combustible roof decks such as steel poured gypsum or concrete only the spread of flame on the top surface of the roof system is evaluated. 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. Fire partitions must extend from the top of the floor below to the underside of the floor or roof sheathing or to the underside of the fire resistance rated floor ceiling or roof ceiling assembly above. The maximum flame spread is 6 feet for a class a rated roof 8 feet for class b and 13 feet for class c.

Helpful documents and resources for usg s roof assemblies can be found on this page. Assembly rated class a roof coverings are those that meet class a standards when combined with other elements. Gypsum panel end joints located midway between continuous channels and attached to additional pieces of channels 54 1372 mm long with screws 12 305 mm. For example shake roofing with a fire retardant treatment rates class b on its own but achieves a class a rating when combined with specified underlying materials such as type 72 roll roofing material.

Have a question about assemblies. Not all ul rated assemblies that use firestone roofing products are eligible for the firestone red shield red shield medallion or platinum warranty. 610 mm with 1 25 4 mm type s drywall screws 12 305 mm o c. These tests may be conducted at ul inc fm global or any other certified testing laboratory.

The firestone standards guidelines and specifications regarding roofing system components and attachment for the warranty desired must be followed. The reduction can also apply when code allows for a corridor wall to be a 30 minute assembly. 5 8 15 9 mm toughrock fireguard c gypsum board or 5 8 densarmor plus fireguard c gypsum panels applied perpendicular to resilient channels 24 o c. The ratings relate to fire tests designed to determine how quickly fire can raise the temperature to unacceptable levels.

Astm e108 defines fire test methods for roof coverings. E108 defines the following conditions. Our range of drawings can help pros plan projects more effectively by utilizing designs for a fire rated ceiling assembly.