I have yet another question. When ever I read about attaching a plywood underlayment to a subfloor it talks about using nails. I can't find any instruction or installation guidelines that note using screws. I have read on this forum that it is possible to utilize screws but I don't understand why all the direction leave out using screws as an option. I will be using a 3/8" plywood over a 2x6 TG subfloor if it matters. Is there an advantage to using nails. Can I get away with screws? Is the fear of screws that they will be over driven????