Any thoughts on whether it's truly ok to install nail down 3/4" hardwoods on a 5/8" T&G OSB subfloor. The house is a new construction and the subfloor is in great condition. No sags. No creaks and the joints are sanded smooth. I'm hoping not to have to add additional plywood as this will increase floor height but if installing it in it's current form will cause a headache down the road, I'd be willing to. I asked my builder and for hardwoods installed by his company, it's routinely done without any additional underlayment (ie right on the subfloor w/rosin paper in between). Any thoughts?