Paperless drywall, 3/8 drywall, green glue. Questions.

I am building a small basement project studio. I am not too concerned about complete sound isolation - as I do not have the budget to be worried about it. I'm not too loud and I do not do critical recording at my home. (I really just need a place to work. My current room is becoming my new baby's room.) I have a handyman putting up steel studs and 1/2-inch paperless drywall with dri core panels as a subfloor on a concrete slab. In the wall cavities will just be fluffy R-13. Construction has not begun yet and materials have not been purchased. So I am open to any other ideas you may have. The question is, I am able to get 15 sheets of 3/8-inch drywall for free. The materials were left over from something a family member did and they are willing to give it to me. Considering that, I may be able to afford to use green glue. However, it would have to go between the paperless 1/2-inch and the 3/8-inch drywall. Is it worth the extra labor for the STC ratings this may yield? I am not able to find any ratings of a similar construction. In addition to the STC ratings, I am slightly concerned that introducing 3/8-inch standard drywall might negate the use of the paperless drywall for stopping mold. My basement is dry - and I recently had a perimemter drain installed that is working very well. If I actually use the 3/8-inch drywall, should that be the inside layer so that paperless is exterior facing? Thank you for all your help.

"I am not too concerned about complete sound isolation" then dont use green glue

Understood... I will take that into consideration. But with all due respect, greenglue does not provide complete sound islolation. Does anyone know what kind of STC rating I can expect with 1/2-inch paperless drywall and 3/8-inch regular drywall and greenglue in between. Since the extra drywall is free, I'm trying to determine if the extra labor is worth it.

Like Lilith said, if you don't need all that much isolation, then the Green Glue is not necessary. To start with, it isn't really glue at all, so you cannot use it to glue your panels together (which is what it sounds like you are thinking of doing). And secondly, what it really does well, is something that you say you don't need anyway, which is outstanding isolation in the low end of the spectrum. So I'm not sure why you still say that you want to include it as part of your construction when it isn't necessary, does what you don't need, and is rather expensive. It just does not seem pertinent to your situation.

Understood... I will take that into consideration. But with all due respect, greenglue does not provide complete sound islolation.

Perhaps not, but there certainly is nothing better for dealing with isolation at the low end. There simply is no other proven product that will get you the same kind of improvement around the resonant frequency of your MSM wall.

... what kind of STC rating I can expect with 1/2-inch paperless drywall and 3/8-inch regular drywall...

You'll find that the general recommendation here is for two layers of 5/8 drywall, not for 1/2 or 3/8. The resonant frequencies of such thin crywall panels are probably going to be too high for them to be useful. Rod recently suggested to another poster than anything less than 16mm is not a good idea at all. I guess there is a reason why you cannot find much published data on walls made with thin drywall: perhaps because it doesn't work very well? - Stuart -

Logicology wrote:

Understood... I will take that into consideration. But with all due respect, greenglue does not provide complete sound islolation. Does anyone know what kind of STC rating I can expect with 1/2-inch paperless drywall and 3/8-inch regular drywall and greenglue in between. Since the extra drywall is free, I'm trying to determine if the extra labor is worth it.

"Essentially, the 5/8-inch-thick version of this drywall consists of two thinner layers (two 5/16 inch, or one ¼ inch and one 3/8 inch sheets of drywall sandwich a sound-absorbing viscoelastic polymer-based laminate layer. " http://ce.construction.com/article.php?L=111&C=409&P=3 Sometimes you have to make up your own mind.

Interesting. Thank you all for your input, I appreciate it. @ Soundman2020: Thanks for your reply. I do understand the construction methods of greeglue, I would be installing it in the typical fashion that they recommend. So it sounds like I need to decide if I want to spend more money and more labor to get negligible isolation effects. Hmmm... :)

green glue = "viscoelastic polymer-based"