Hello I have just purchased my first amount of 3/4" thick hardwood flooring and am trying to figure out if I was sold the correct underlayment. I purchased quiet walk with the vapor barrier attached. This flooring is going on the first floor over 3/4 OSB. Is this ok to put nail down flooring over the quiet walk. It says put the blue vapor barrier up for laminate and floating wood floors. Do nail down floors follow the same? Please help

When I was installing out of LL we always used QuietWalk for strictly floating installations. Insulayment ( also manuf. by MP Global ) was for gluedown & naildown. Infact I'm looking at the LL brochure, and that's what they still specify.

Contact your wood flooring mill and see what they require(not recommend) under their product, in order to have a full warranty.

Call QuiteWalk and ask them if they sell their product to be placed under a nail down product.
http://www.mpglobalproducts.com/
It contradicts itself in the installation PDF
It says not suitable for gluedown wood, but says nothing about fasten down wood. But further down it only mentions engineered floating wood floors. Says nothing about fasten down floors.