I will be installing 3/4" solid hardwood over crawlspace subfloor. I have read the entire site on what type of underlayment should be used in this application. It seems that traditional 15 lb felt paper is the recommended, and a 'moisture barrier' is not recommended for my installation as trapping moisture under the right conditions could be detrimental.

My question though is about Quietwalk. Its has sound adsorbing properties, but also is noted as a moisture barrier. Should I not use this under 3/4" solid nail down floor over a crawlspace subfloor? I have existing hardwood floors (about 16 years old) with not signs of moisture damage...

Any help would be appreciated.

thanks.

-R. Hess