Fire Ratings Of Sheet Metal

Sheet metal penetrations are used in rated assemblies and when correctly fire caulked become part of that assembly.

Fire ratings of sheet metal.

It usually consists of two or three coats over metal reinforcing mesh. A one inch 2 54 centimeter layer of stucco can easily lend a 1 hour fire rating to a wall source. Roof eaves overhangs are a fire hazard but they can be protected with an encasement of fire resistant material. Type x gypsum board is wallboard to which non combustible fibers have been added.

Rockwall fire rated wall panels consist of a unique rockwool mineral fibre core called conrock with laminated sheet steel permanently bonded to both sides. When 28 gauge steel deck is used the restrained assembly rating 1 1 2 hr. Fire ratings are based on an assembly. Noncombustible steel construction reduces structure flammability and can provide up to a four hour rating on walls.

All the mbma fire rated designs utilize the generic 5 8 inch type x gypsum wallboard as a minimum so any gypsum. 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. 1 restrained beam rating based on the period of fire exposure where the beam sustains the applied design load but not more than twice the corresponding unrestrained beam rating and provided the later is 1 hour or more. When 9 16 inch steel deck is used the restrained assembly rating 1 1 2 hr.

The most common fire rating material used in metal buildings is gypsum wallboard. Astm e119 tests on loaded structural steel and composite steel concrete beams are always restrained and result in 2 ratings. Quarles senior scientist insurance institute for business home safety richburg sc. Rated floors often use sheet metal pan decking most often with a pour of light weight or standard concrete on top.

But when it is used one on each side of a properly framed wall it can become a fire rated wall. Once rockwall panels have been installed according to the specific intertek warnock hersey certification guidelines the assembly provides 1 2 and 3 hours of fire resistance with a 4 5 and 6 core thickness respectively. However this doesn t make a building fireproof. According to the book commercial drafting and detailing a typical one hour fire rated wall consists of 2x4 studs spaced 16 inches from the center of one stud to the center of the next covered by 5 8 inch type x gypsum board.

I am not aware of a fire rated wall assembly using sheet metal. One sheet of 5 8 type x sheetrock has no fire rating. And 2 unrestrained beam rating based on the period of fire exposure where the average measured temperature at any section of the steel beam. Other materials can be used including concrete masonry for walls and spray applied fire resistive materials.