Solid Hardwood, Engineered and Laminate Flooring - best subfloor for hardwood

I will be installing 3/4 solid maple hardwood in my house. My subfloor currently exists of 5/8 plywood under 3/8 particle board. Everything is in good shape. The house was built in 1974. I'm reading that the particle board will not hold the nails very well for the hardwood. There currently is wall to wall carpeting.

I'm installing the hardwood in my kitchen, LR, and DR. I already have the particle board ripped out in the kitchen because the glue from the linoleum stuck to it really good, so instead of scraping it off, I just ripped it out.

So my question is, should I take out the rest of the particle board? If so, what should I replace it with?

Thanks,
Josh

Take it up and replace it with 3/8" plywood. I prefer the BC underlayment grade when the plywood is thinner than 1/2". Best to screw it down and don't try to hit any joist.

You will have to let the new plywood adjust to its new home before you start laying that maple. You need a moisture meter when you are installing maple. The maple and the plywood should be within 2% of each other to be on the safe side.

What is the reasoning for not hitting a joist?

Underlayment should never be intentionally nailed to the floor joist. You want both layers of plywood to move together. The subfloor should be glued and nailed securely with 2" to 2 3/8" ring shanked nails. Then the underlayment goes on top perpendicular to and and offsetting the subfloor seams . The underlayment should either be screwed 6" OC on the edges and 8" in the field. You can use underlayment staples but you would need a pneumatic stapler to do that. Some guys don't like to glue the underlayment to the subfloor. I do, using several beads of yellow wood glue. The only time I do not glue is if there will be cement board and tile over it instead of a wood floor.

The most important thing is to re-nail that subfloor securely because it is likely not to be a T&G, probably a a square edged CDX grade. CDX has a lot of voids in the center plies, unlike an underlayment grade which has no voids.

Jerry,

Yes, the subfloor is CDX. I've noticed a lot of the nails need to be pounded back in. I'm not sure if they popped up when I was pulling up the particle board, or they were like that before. I am also going to go through the whole floor for sqeaks and use screws to get rid of them. I might staple the underlayment down. What length and gauge staples should I use?

The UL stapler is on my tool list for this year. I think Senco and Bostitch make one but I don't know much about them yet :) .