Wall construction question... what to do?

[Dr. J]

My main live room has 2 walls that are concrete basement walls,
With nothing but earth on the other side. (The other 2 are inside walls.)

I am framing all the walls with 2x4 studing & finishing it with 5/8 gypsum,
and possibly sound board (If needed?).

My question is, since these 2 walls are concrete, , should I use any
resilient channels on these walls, or is it overkill?
Is the simple fact that there is nothing but earth on the other side of the
concrete good enough for those 2 walls, and just go with a basic
framing sceme with no resilient channels?

Thanks for the replies
Dr. J

[knightfly]

Flanking sound (structure-borne) travels really well in concrete - so even if the earth covers ALL the concrete that is directly in contact with your room, there is an excellent chance that any structure-borne noises from above would travel down the concrete wall and radiate into your room as airborne noise.

I'd go ahead and use RC on even those walls - it doesn't cost all that much more, and would likely help reduce the need for quite as much bass trapping by acting a little more as a diaphramatic absorber.

Also, by using RC and being careful not to "short out" the RC to the studs, you can screw both layers directly to the RC without the need for any special "laminating" screws or glue, and without worrying about the loss of isolation caused by screwing multiple layers directly to studs... Steve

[Luke]

Hi Steve,

I can tell you from experience that with 2 concrete walls/earth, I have never had any leakages from outside. But my basement is totally underground. (No windows!)

Thanks for the tip on the RC (Not having to laminate the 2 drywalls sounds good to me!)


Cheers!

Luke

[knightfly]

Hey Luke - not quite finished with your drawings, but getting closer -

I wasn't worried about outside noise, more structure-borne from upper levels travelling down frame into concrete and possibly radiating into the room that way - sounds wierd, but it's happened - ANY continuous rigid path will do this, more than one high-dollar apartment has been screwed for isolation by someone thinking they knew more than the designer and bridging things that were meant to stay separate... Steve

[Luke]

Steve,

Right, I should have paid closer attention to what you said