Bubble radiant barrier vs radiant barrier and r15 insulation

[BigBoss]

Bottom floor has radiant in the concrete, second floor is radiant Pex under floorboards. We want to soundproof between the 2 floors. What I have seen is to use the bubble radiant barrier 2 inches under the Pex. Would non bubble radiant barrier with R-13 soundproof insulation under that be just as good or even better? Looking for thoughts, couldn’t find much online about that combo. Thanks

 

[Fitter30]

There's lots of info on you tube. This guy is petty good. Sound proofing is more of a science
https://en.m.wikipedia.org/wiki/Sound_transmission_class[/URL]

https://m.youtube.com/@HomeRenoVisionDIY

 

[Sponsor]

 

[wwhitney]

The bubbles in the radiant barrier do basically nothing. And an upward facing radiant barrier will become fouled by dust over time, even I believe in a nominally sealed joist cavity.

So if you want a radiant barrier, the shiny side should face down, and then it doesn't matter if the top side is in contact with the radiant tubing, or if there is an air space above. But you need to leave an air space below the shiny side so that it's not in contact with anything.

Below that airspace, insulate however you like for both sound and thermal.

Cheers, Wayne