Using Sound-Deadening Boards

Any ideas on using these boards (Home Depot brand). I am building a single layer of 2x4 wall with rigid fiberglass in it. Is it ok to sandwich a 1/2" sound-deadening-board in between a 1/2” and a 5/8” sheetrock (5/8” being the last layer)?

Sure you can do it. It will not be as effective as using a third layer of sheetrock, but it is your money. Andre

AVare wrote:

Sure you can do it. It will not be as effective as using a third layer of sheetrock, but it is your money. Andre

Thanks Andre, I naively thought using a layer of these boards would be more effective. :oops: I’d rather use 3 layers of sheetrock if that is the case. Is this a good order and thickness: Insulated 2x4 frame> 5/8”> 1/2”>5/8” Thanks for all the help. Alex

That'll work fine.

As Aaronw wrote: that will be fine. Andre

Thanks Andre Aaron, How about gluing the last layer with liquid nails, would I gain much? Is 5/8” sheetrock too heavy to glue on?

AlexT wrote:

Thanks Andre Aaron, How about gluing the last layer with liquid nails, would I gain much? Is 5/8” sheetrock too heavy to glue on?

The word on glue is indecisive. Personally I would not, or if I did, glue AND nail. Glue only adheres to the surface of the sheetrock. Andre

IS your wall made so that both sides have the wallboard directly attached? IF so, you would probably get slightly better mid-high frequency isolation by using the sound board on ONE side only, placed directly on the studs then 1/2 then 5/8 wallboard. The sound board DOES have a slight decoupling effect. Fasteners will couple sound through solid wood frames, and when both sides are solid coupled the insulation doesn't help this from happening. The only thing to be done in this case is to use twice the space between fasteners on all but the final layer, then full schedule fasteners on the final. On this type wall, you would get noticeably better isolation (in upper frequency ranges) by mounting the wallboard layers on one side of the frame using Resilient Channel, or Hat Track mounted on RSIC clips (rubber shock mounts) - The RC raises the cost by about 25 cents per square foot of wall, the RSIC method about 50 cents per square foot of wall. If you resilient mount one side, forget the sound board; it's twice as expensive and half the mass of sheet rock, not a good plan. In any case, you want complete insulation fill with slight compression, this damps the wallboard panels to control ringing. Glue - As Andre said, only WITH fasteners. Also, you do NOT want to full-face glue between layers, this causes the glued layers to act as one material - you get better attenuation when each layer can flex on its own, because then each layer has its own "coincidence frequency", where it is weakest - different thicknesses of wallboard, or different types of material, each has its own coincidence frequency and when these are DIFFERENT you have less of a "hole" in the isolation response. HTH... Steve