Hi everyone,

I'm installing 3/4" Pollmeier beech, 4 inch wide plank.

I've got a 5/8" OSB subfloor (16 oc) which I'm beefing up with 3/8" CDX plywood for a total of 8/8 (1"), screwed and possibly glued.

Questions:
1 Is that subfloor adequate?

2 What screw length (or ring nail?) should I use to hold the ply to my OSB? Should it puncture the back of the OSB, or would it be best to not puncture the OSB?

3 Is gluing necessary? What glue and how much?

Ok, so once the subfloor is done, I'm going to install the 3/4" beech. I plan to use a bostitch MIII FS or FN, depending on what you guys recommend.

Questions:
1 Nails or staples? I know there are lots of discussion/opinions, but what I'm noticing from the long discussion thread is the opinions are influenced by the subfloor type. Some people say nails in plywood, staples in OSB, etc etc. In my case, I'll have 3/8" ply on top of 5/8th OSB, so I sort of have a combo! =) Any thoughts? The manufacturer mentions cleats in their installation docs, but that likely assumes a ply 3/4" subfloor.

2 Length of fastener - How long? Should they pierce the OSB? I don't want to blow the back out of it. Keep in mind I have the ply/OSB combo subfloor, total 1".

3 Brand of fastener - I'm thinking Bostitch, since they make the tool.

In researching this issue, I've discovered there are a lot of opinions and they differ based on subfloor. I think it would be helpful to have a reference table, where you could see things like faster type, length, etc based on subfloor all in one place.

If you guys think it's a good idea, I'd be willing to collect your opinions and build the table, and maybe an admin would sticky it. Let me know what you think. The goal would be to make an easy to find reference, and to reduce the repetitive nail/staple/subfloor thickness questions.

John

John, you are Ok using a 3/8" plywood underlayment if the 5/8" OSB is a T&G subfloor grade as opposed to 5/8" OSB sheathing grade that has no T&G. Having the T&G is critical here when you're talking subfloors.

I install alot over OSB and Advantek... I much prefer 2" staples. I use yellow wood glue on underlayments. I have heard the argument for not using any glue... and it has merit if you use staples or nails to install it. If you screw the UL down it all becomes a moot point.

Hi Jerry, long time since I posted that message.

I went with screws, 6-inch grid, 4-inch perimeter. I JUST FINISHED IT.. Took a while, but there was 1500 sf to do, and installed a new furnace myself too!

Anyhow, I'm getting ready to do the floors, we went with a 3/4 solid beech Pollmeier 3-15/16" plank.

I'm sure I'll post lots of newbie questions, and hopefully success pics!! =)

Thanks for your advice.

You're almost as fast as I am JD.