Installing hardwood on OSB: fastener type and length? Blowout??

[michaelbarry06]

DIYer here, new to flooring, looking for advice on my hardwood flooring situation.

Current subfloor: 3/4 inch OSB, structurwood edge gold (4x8 foot sheets, T&G)
Joist spacing: 16 inches on center
Plan: 3/4 inch red oak T&G, run perpendicular to joists. Will use 1/8 inch insulayment material for sound dampening, as this will be on the 2nd floor of home (above grade).

My research has shown that hardwood directly on top of this OSB is acceptable. I realize not the best. But acceptable. Especially since the OSB is sound condition (intact), no deflection, no movement. And making sure my hardwood is perpendicular to the joists. So moving beyond that area of debate..

My question is regards to type and length of fastener. I've read for installing oak on OSB, staples are preferred over cleats, as they have better holding power in OSB. Is this accurate?
My next question is: should I be very concerned with blowout in OSB when choosing length of fastener (staple OR cleat)? Does blowout automatically mean loss of holding power leading to loose/squeeky boards in months/years? Measuring the depths of drive of fastener (from on top of tongue to bottom of OSB, at 45 degree angle) my measurements are:
2 inch staple would extend 1/4 inch beyond bottom of OSB (= blowout)
1-3/4 inch staple would EXACT depth of bottom of OSB (possible blowout??)
1-1/2 inch staple would fall 1/4 inch short of bottom of OSB (likely no blowout, BUT is this enough holding power??)

I'm running in circles trying to figure this out, and delaying my project each time in doubt. I think the insulayment layer (adding 1/8 thickness) is leading me not to choose 1-1/2 inch staples, whereas without that thicker layer I would have! If anyone has any knowledge or opinion, I would appreciate your words of advice! (Aside from the debate of OSB vs plywood.) Thanks!

 

[highup]

I can't help you other than recommend the fastener that doesn't come out the other side...... but 1/4" isn't that much. I'm thinking the 1 3/4 for exact depth. Plywood is of course the best bet, but I'd bet the Gold edge is superior to any generic brand osb for holding power.

 

[michaelbarry06]

Thanks for your opinion Highup. I appreciate it. I agree, 1/4" sounds negligible. And I'm sure gauge fastener, cleat vs. staples, etc. are all considerations in degree of blowout. A controlled study seems necessary to really determine the correct answer. You bring up another question I've wondered in all my research: How many contributions on forums in the OSB vs. plywood subfloor debate are referring to regular OSB, not the improved/enhanced 3/4 inch edge gold/advantec/etc. OSB. Just to give you an idea of my uncertainty, another response I received on another forum is that 2 inch staples will be fine. Blow out won't be too big of an issue. If wanting extra hold power, staple every 8 inches and hit the joists. I understand how no one wants to give or has a clear, precise answer.

 

[highup]

It is hard. You find arguments between wood installers..... Cleats or staples? Both have been installing for 20 years, yet they disagree.
When a fastener penetrates clear through the floor, think of of it like this. Drive a 3" long nail into the 3/4" OSB, the drive a 3/4 inch nail into the OSB. Which holds better?
The longer nail reamed a hole in the floor as it continued going long past where it was useful.
If the nail goes through the OSB, and only 1/4" further entering the joist, I'm not sure that's beneficial. Maybe the opposite.
I'm not a wood guy, so I'm throwing my logic at you as food for thought.
I wonder what Weyerhauser would have for advice..... and the maker of your floor.