First off, thanks for making this site so great! I have learned a ton from all your help. My GC stated that he likes to glue and nail any hardwood 3" and over. I just wanted to check with the experts and verify if this is good to practice. This flooring will be over our finished basement and on the main level where the flooring will be installed, I have a 150 gallon fish tank in my office that tends to keep the RH noticable. I will get a barrameter to check out the levels, but i am bringing it up to you all so you can chime in on whether or not these should be concerens and what I can do to address them.

We went with Mullican's Williamsburg line, 1600 sqft of 3/4" x 4" solid oak plank laid over 3/4" OSB (Orientated Strand Board) T&G subflooring.

Reading some posts here, it looks like OSB is not the best underlayment, so maybe glue and nail is best. Is it better to staple or nail over OSB, should I make certain on the length of the staple/nail?

Please let reply and let me know best practice for this application.

Thanks! Joe

The rule is over 5 inches but some like to do 5 inches and over. You can always do it if you want especially if you think the underlayment is in substandard condition. It's cheap insurance.

I certainly dont think your GC gave you bad advice. I consider it every time I install anything over 2 1/4". But your subfloor IS substandard. And if your basement is concrete (most are) will you be using shorter staples? If so definetly glue also. Nail to joists too.