We're often asked; can cork underlayment work to reduce noise from the upstairs floors before we install new solid hardwood? Or... can I use the standard roll stuff that comes in 1/4" thickness?
The answer lies in a few questions asked first. In the case of the example above we're dealing with a standard 3/4" plywood subfloor where the new hardwood will be nailed or stapled. If you're seeking to eliminate squeaks that are now heard under the carpeting cork is not the answer. But once some repairs are made to the squeaky areas cork will definatly muffle or quiet and sometimes eliminate foot traffic sounds. It is not exact as other factors come into play.
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For instance. If the subfloor is uneven, boards will have a tendency to rub against one another, or up and down. Cork underlayment will suppress the noise but it will be heard when walking on that upstairs flooring area. For the underlayment to work effectively one needs a flat subfloor substrate to work with.
Okay. But You're Adding 1/4 of an Inch Under The New Hardwood. Will the Fasteners Hold?
This one is up for debate. Considering a standard flooring staple or nail used for plywood over floor joists systems is two inches in length and penetrates 3/4" plywood by approximately 3/8 of an inch, you're not really losing anything. On the other hand, if you're nailing through the plywood into the joist system (which I rarely see being done) you do lose some of the grabbing power of the joist system.
All are welcome for debate!
Posted in: Installation Techniques
