Fire Rating Of Sheet Metal Ductwork

One sheet of 5 8 type x sheetrock has no fire rating.

Fire rating of sheet metal ductwork. I am not aware of a fire rated wall assembly using sheet metal. Flameshield we are one of only a few uk companies licensed to manufacture flameshield fire rated ductwork compliant to bs 476 part 24. Like show 1 like 1. Question asked by sahawnehmajdi on sep 30 2019 latest reply on oct 5.

There are some fire tested wall assemblies that are tested with air duct passing through it. The fire tests conducted by swri indicate the 22 gauge metal duct will provide at least a 2 hour fire rating between the fire damper and the barrier. Sheet metal penetrations are used in rated assemblies and when correctly fire caulked become part of that assembly. The ducts minimum 22 gauge sheet metal construction are for ventilation purposes only and contain no combustible material within the duct.

But when it is used one on each side of a properly framed wall it can become a fire rated wall. When 9 16 inch steel deck is used the restrained assembly rating 1 1 2 hr. Fire ratings are based on an assembly. Rated floors often use sheet metal pan decking most often with a pour of light weight or standard concrete on top.

Galvanized steel ducts fire rating. They are usually 10 x 10 sized ducts.