Wood floors and a Sound-proofing question

[Ted White]

Very common concern that sometimes causes people to sell and move. The problem can be divided up into two considerations:

#1 There is predominantly airborne noise. TV, stereo, etc.

#2 There is predominantly footfall (impact) noise.

These two scenarios require different solutions.

In situation #1 you would not prefer to introduce an underlayment. Doing so will create a compressible layer, which will have a resonance. Any compressible layer between two layers of mass will have a resonance. This resonance will hurt our sound isolation efforts at some frequency range. so for airborne noise, we avoid this.

In situation #2, however, there is such a large amount of energy in such a small area (heel of a foot) that we have to look at the compressible layer despite the fact that it introduces a resonance. Generally 1/4" to 3/8" thick underlayment.

If you are using an engineered floor (no nail-down) this can float atop a suitable underlayment.

If you are using true 3/4" nail-down hardwood, you cannot nail through the underlayment. You would need to float a layer of subflooring on top of the underlayment to give the nail-down Hardwood something to nail into.

More info here: How to Soundproof a Ceiling | Soundproofing Ceilings Solutions | Soundproofing Company

[Jukesgrrl]

While laminate floors may reduce the problem of dust mites in carpets, the product still releases “off-gas” VOCs. "Several studies suggest that exposure to VOCs may make symptoms worse in people who have asthma or are particularly sensitive to chemicals."

Volatile Organic Compunds (VOCs) in Your Home - EH: Minnesota Department of Health

[Ted White]

Many carpets, pads and drapes as well as plywood have the same problem.

[ZeroTiger]

cork is a great underlayment for sound. We put that on the main level under the bamboo. Can't hear much in the basement. If you do cork, get the sheets instead of the roll. Your installer will thank you.

[Ted White]

Cork doesn't test as high as an engineered underlayment and because its organic mold can be an issue

[JP Groenewald]

For a new floor, first install soft board sheets direct on the beams and then your wooden floor planks. Most efficient of the less costly methods. For a nearly perfect solution fist cover the soft board with a thick layer of steel wool or similar material and then your floor planks. (Regards from South Africa.)