Galvanized Sheet Metal Fire Rating

Studies done on the effect of low temperature environments on hot dip galvanized hdg steel indicate the minimal change in the behavior of the galvanized coating.

Galvanized sheet metal fire rating.

A galvanized sheet by itself would not have a fire rating. The load bearing capacity of corrugated steel without fire protection is 15 30 minutes depending on the structure. When there is no insulation used on top of the corrugated steel sheet the heat goes through the metal and dissipates upwards and the. Temperatures in fires can easily exceed 1 000 f.

Building with fire safety in mind. There is a potential for coating damage but many have found fire damage to minimal on galvanized steel. Chapter 8 fire resistive materials and construction nfpa 5000 building construction and safety code nfpa quincy ma 2006. For 2 hour unrestrained assembly rating.

The ratings are for unsymmetrical walls that require ratings from both sides. Sheet metal penetrations are used in rated assemblies and when correctly fire caulked become part of that assembly. Galvanized coatings perform well under extreme cold and hot temperatures. V421 which pro vides 1 and 2 hour fire resistance ratings for exteri or walls in metal buildings.

The code requirements for fire resistance of metal panels are logical and not overly burdensome. 1 5 16 inch steel deck w clear span 91 inch supported by w6 x 18 or w8 x 18. Fire ratings are based on an assembly. One sheet of 5 8 type x sheetrock has no fire rating.

Occasionally the american galvanizers association gets the question of whether the galvanized coating is adversely affected by exposure to fire. Average thickness 119 μm temperature of galvanizing 460 c 1 specimen admixure al in galvanizing bath department of steel and timber structures training school malta motivation fire test 2010 heat transfer in fire technology fire test 2010 fire test 2011 real structure fire test 2011. 1 5 16 inch steel deck w clear span. The mbma fire tests of exterior walls in 1997 resulted in a new uldesign no.

If combined with gypsum or other materials in an assembly it. Fire ratings are generally based upon testing of a structural sample. I am not aware of a fire rated wall assembly using sheet metal. Rated floors often use sheet metal pan decking most often with a pour of light weight or standard concrete on top.

Specifications methods to determine fire resistance ratings for generic designs can be found in most building codes e g chapter 7 fire resistance rated construction international building code international code council falls church va 2003. Most metal panel manufacturers have tested their roof assemblies and most if not all metal panels and shingles can be used in class a fire rated roof systems. The steel sheet bends but the load bearing capability remains for a significant amount of time. But when it is used one on each side of a properly framed wall it can become a fire rated wall.