Change order of RC in UL listed Floor Assembly

[Ryan Schultz]

I probably know the answer to this already, but just wanted to verify.

In the following floor assembly, is it possible to have RC channel attach directly to the joists, and then have the (2) layers of gyp bd. outside that?

• RC
• Gyp Bd.
• Gyp Bd.

Or do we have to stick to the following order...

• Gyp Bd.
• RC
  
• Gyp Bd.

http://database.ul.com/cgi-bin/XYV/...n=versionless&parent_id=1073984818&sequence=1

 

[Builder Bob]

The assembly was tested as depicted in the illustration - any changes to that installation makes the installation null and void.This includes using any other materials or manufactures that are listed....

 

[steveray]

You may be able to find an equivalent assembly constructed in the alternative manner if that helps....You should not "Have" to use the original assembly by code, code will just care for fire and STC rating to be the same...

 

[fatboy]

I agree with both answers, no, you can't just change a listed, tested assembly, and yes, you probably can do some searching and find a listed, tested assembly in the order you are describing..