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.

When there is no insulation used on top of the corrugated steel sheet the heat goes through the metal and dissipates upwards and the. Occasionally the american galvanizers association gets the question of whether the galvanized coating is adversely affected by exposure to fire. Temperatures in fires can easily exceed 1 000 f. 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.

Chapter 8 fire resistive materials and construction nfpa 5000 building construction and safety code nfpa quincy ma 2006. If combined with gypsum or other materials in an assembly it. Building with fire safety in mind. For 2 hour unrestrained assembly rating.

Fire ratings are generally based upon testing of a structural sample. V421 which pro vides 1 and 2 hour fire resistance ratings for exteri or walls in metal buildings. The mbma fire tests of exterior walls in 1997 resulted in a new uldesign no. 1 5 16 inch steel deck w clear span.

There is a potential for coating damage but many have found fire damage to minimal on galvanized steel. One sheet of 5 8 type x sheetrock has no fire rating. Galvanized coatings perform well under extreme cold and hot temperatures. 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.

But when it is used one on each side of a properly framed wall it can become a fire rated wall. The load bearing capacity of corrugated steel without fire protection is 15 30 minutes depending on the structure. 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.

Sheet metal penetrations are used in rated assemblies and when correctly fire caulked become part of that assembly. 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. Fire ratings are based on an assembly. 1 5 16 inch steel deck w clear span 91 inch supported by w6 x 18 or w8 x 18.

1 1 2 hour unrestrained assembly rating. In fact hdg coatings do not show any significant differences in corrosion rate in temperatures below 40 f. The code requirements for fire resistance of metal panels are logical and not overly burdensome. The thickness and number of the layers of type x gypsum wallboard are specified for each.