Auralex RC-8 over existing drywall?

[Jbbeaubeaux]

Does using Auralex RC-8 over existing drywall to attach another layer of new drywall create a third leaf effect?

Would it be better to remove the existing drywall, install the RC-8 on the studs and then new drywall?

[Scott R. Foster]

yes and yes - but is it worth the trouble? Depends on the characteristics of the existing wall [what's on the other side / what kind of studs and their spacing / is the interior insulated / what is the thickness of the drywall you have / et cetera] and your goals.

[Jbbeaubeaux]

Scott,

Thanks for the feedback. I appreciate it.

My wife's Voice Over business is growing so I am moving her studio into a 4.5' x 4.5' walk in closet.

The closet is in the center of the house, with bedrooms and bathrooms surrounding it.

The main source of noise is a tenant below who occasionally plays musical instruments. When he plays it is as if he is in the closet, sound right up through the floor.

I am planning to build a floating floor on top of Auralex U-boats using 2 x 6 joists 16 oc, regular insulation between, then 3/4" plywood, a layer of Auralex SheetBlok, and then 3/4" MDF, then thick carpet padding, then berber carpet. I hope that helps cut most of the voice from below.

The four walls are your typical interior 2 x 4s 16oc, no insulation with probably 1/2" drywall.

I have Auralex RC-8 that I want to use but my research indicated if I put the RC-8 on top of the existing drywall I would create a third leaf.

Here is my plan. Do a good job on the walls, with no stupid mistakes, and see what we hear from outside sounds. If we don't like it, I want to be able to add either a layer of SheetBlok and a another layer of drywall.

My biggest fear is I make a mistake by leaving the existing drywall, put the RC-8 on top of that drywall then attach drywall to that and I create an impossible problem that no amount of additional treatment can fix.

Does all this make sense?

Thanks!

Jim

[Scott R. Foster]

Room in room only makes sense when you improve all the partitions - given you plan a floating floor I'd guess a redo on the walls / ceiling / door are in order. Rip it all out IMO.

[Jbbeaubeaux]

Scott,

Thanks!

I think I will remove the old drywall and attach the RC-8 directly to the wood studs.

One last question (maybe).

I am toying between attaching to the RC-8 either QuietRock 510 drywall all by itself, or layering 5/8" type X drywall, then SheetBlok, then 1/2" type X drywall.

Or the other option and use green glue instead of the SheetBlok between the two layers of drywall.

Do you know which choice would give me the highest STC?

Thanks!

Jim

[Scott R. Foster]

I suspect insulation stuffing / resilient channel / and a couple of layers of drywall would do the trick. But rip the top layer off and post pics - then ask again.

[bert stoltenborg]

How's the floor from neighbour below up constructed?
If you know that you maybe can calculate the results of different new constructions.