Best underlayment for sound?

[flynnecf2]

I'm about to install 1/2" locking solid stranded bamboo throughout my 1st floor and Ill be floating it over a wood subfloor. I want an underlayment that will make the floor both sound and feel like the real thing...as much as realistically possible, at least. I'm not concerned about noise transmission to the finished basement below, and I'm in a dry climate so I don't think that I'm concerned about having something that also acts as a vapor barrier (?).

I'm leaning towards either a high end foam (Floor Muffler, or similar) or cork. Some parts of the internet say that cork is the best, in terms of "sound dampening"....but I don't know if that means that it doesn't transmit sound to the rooms below or if it means that the floors will sound more "solid" (not hollow or clicky).

But I've also heard people say that the upper end foam underlayments are now better than cork, and cheaper. So, what does everybody think?

Thanks,
Eric

 

[Nick]

cork..

 

[flynnecf2]

Thanks Nick. What about the cork thickness? I'm guessing it's between 1/8" and 1/4". I've been warned not to go too thick with underlayment and wondering if I should be concerned that the 1/4" will feel squishy and might even possibly break the click lock from sinking into the cork.

 

[Nick]

Cork is pretty dense . I wouldn't worry about it ..

 

[flynnecf2]

Ok, I'm trying to talk myself into cork....but one last question. Are the STC and IIC ratings to be taken as the "end all" comparison of how "solid" the floors will sound? I see that 1/4" cork is rated way lower than the Floor Muffler (links below). Or are there other factors involved that those ratings don't account for?

Cork: STC rating of 52 and IIC rating of 51
Floor Muffler: IIC74/STC73

Oh, and do I need to glue it down? (sorry, I guess that's 2 questions)

Cork: https://www.amazon.com/dp/B007OSICIS/?tag=skimlinks_replacement-20

Foam: https://www.amazon.com/dp/B005IPLWQ8/?tag=skimlinks_replacement-20

 

[Ernesto]

Cork is less squishy that all of the cheapo underlayments out there and even the best ones

 

[Nick]

A lot cheaper then the good rubber to ..

 

[highup]

I'm about to install 1/2" locking solid stranded bamboo throughout my 1st floor and Ill be floating it over a wood subfloor. I want an underlayment that will make the floor both sound and feel like the real thing...as much as realistically possible, at least. I'm not concerned about noise transmission to the finished basement below, and I'm in a dry climate so I don't think that I'm concerned about having something that also acts as a vapor barrier (?).

I'm leaning towards either a high end foam (Floor Muffler, or similar) or cork. Some parts of the internet say that cork is the best, in terms of "sound dampening"....but I don't know if that means that it doesn't transmit sound to the rooms below or if it means that the floors will sound more "solid" (not hollow or clicky).

But I've also heard people say that the upper end foam underlayments are now better than cork, and cheaper. So, what does everybody think?

Thanks,
Eric

There's a product called Floor Muffler that works really well with laminate flooring. I don't know why it wouldn't work with bamboo that thick. It's really lightweight material and doesn't feel like it could do much, it does.
Your best test would be a golf ball, D) some cork, some floor muffler, and a piece of laminate flooring (not bamboo)
Do a test using the Floor Muffler and the cork layed under a small piece of laminate flooring.......... let's say an 8" square piece of laminate. Bounce the golf ball on it from bout a foot high and listen to how it sounds. Go back and forth between the Floor Muffler and the cork a few times and see how each one sounds. ...for kicks and giggles also include a piece of super cheap foam in your test. That one is gonna sound really hollow compared to either of the others.
I think laminate flooring might be a better test since it is a lot harder and denser than the bamboo........... that is, more prone to be noisy to walk on.

 

[Ernesto]

My go to underlayment is SoundSolutions with vapor Block. It does not crush like Floormuffler and its got weight to it. Floormuffler is junk.

http://www.healthierchoice.com/sound-solution.html

 

[highup]

Floor muffler crushes? From knee pressure when you install it? I've seen Floor muffler from tearouts and it looks fine. You see the outlines of the planks but it's not "crushed" Weight doesn't mean anything. If weight was good lead cars would be better than aluminum cars.

 

[Ernesto]

Yes from knee pressure. I can lift a roll of that junk with my pinkie, maybe ten of them.

 

[highup]

There's no knee pressure once the flooring is installed. The load is distributed.
Ever seen that tile 'underlayment' made of styrofoam balls surrounded by a little cement? I'm sure it's damaged pretty easy with a hammer blow as compared to cement board. The test is how it performs as designed under the product, not your knees.
Not saying floor muffler is the best ever made, but it deadens sound 10X better than the cheap blue gift wrap foam that Pergo and Wilsonart used to sell.
If ya like heavy stuff, buy that 100lb roll made by Gates

 

[Ernesto]

Here is a really really good underlayment. It's sold here in town and called Titanium. Foil has the highest perm rating for films. Foil and rubber, very heavy.

https://www.floorsave.co.uk/rubber-underlay-with-foil-vapour-barrier-10m2-roll.html