Roof Ceiling Fire Rating

Ul and fm list many roof ceiling systems in their publications.

Roof ceiling fire rating.

A question has come up concerning sloped roof trusses and fire assembly ratings. Astm e119 standard test methods for fire tests of building construction and materials is the test standard for determining the fire resistance rating of partitions floor ceiling assemblies roof ceiling assemblies beams and columns. Urb concealed grid system and tile. 3 4 fr 83 12 x 12 z runners fluorescent type none 2 1 2 concrete.

The maximum flame spread is 6 feet for a class a rated roof 8 feet for class b and 13 feet for class c. Floor ceiling and roof ceiling systems were fire tested at less than 36 inches total depth. Fire tests may be conducted at any one of several recognized facilities. Helpful documents and resources for usg s roof assemblies can be found on this page.

12 x 24 2 x 4 8 w10 x 25 beam floor units and beam support 3 hr. As a designer and installer you should know the fundamental differences between a suspended ceiling which is an integral part of a fire rated floor ceiling or roof ceiling assembly and the far more. The slope of the test specimen is preselected and since steeper slopes are more of a challenge due to melting material feeding the fire the rating applies to the maximum slope passed. However the total depth of the systems with either directly attached or suspended ceiling membranes shall be permitted to extend greater than 36 inches.

Where the room side fire resistance rated membrane of the corridor is carried through to the underside of the floor or roof sheathing deck or slab of a fire resistance rated floor or roof above the ceiling of the corridor shall be permitted to be protected by the use of ceiling materials as required for a 1 hour fire resistance rated floor or roof system. Ul tests rate an entire assembly. Refer to our roof ceiling assembly documents which includes ul fire rated roof assemblies for easy guidance through the assembly of a roof or ceiling on your next project. Fire rated ceiling assemblies suspension ceiling designs floor ceiling designs a003 3 hr.

No ceiling or suspension system product alone constitutes a fire rated assembly. You can use only the specific type size and minimum. Some are reluctant to rely on test results from flat parallel chord trusses applied to sloped roof trusses. Do you have any information regarding the suitability of the fire rated ceiling assemblies for sloped roof trusses.

Don t be left hanging understanding how the nec regards suspended ceiling designs and supports is critical for proper design and installation of electrical wiring and equipment. In the world trade tower collapse heat load on the connections of steel trusses is suspect. Both ul and ga include specific guidance regarding the use of insulation in assemblies. Concrete with cellular steel 3 hr.