commercial building use wood stud, can they put one more

[archi4er]

layer drywall to meet code? otherwise the contracter must replace all the wood stud with metal stud.

or any other solutions?

[LeCorbusier]

there are 2 hr wood stud stud assemblies. And yes, you can usually add a layer of gwb to achieve this, but you should check with the local inspector or local codes. In NYC for example, you cannot use wood studs at all. Check the US National Gypsum Board Association for fire rated assemblies. http://www.gypsum.org/

http://www.gypsum.org/codeservices.html

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