About two months ago, I finished installing 3/4 solid white oak in the downstairs of our house. We have a basement, so the wood was installed over 3/4 plywood with a minimum of 15# felt paper.

Many areas of the floor were in bad shape when it came to flatness. In some areas, I used a lot of 30# felt to try to bring everything up to standards.

So now two months later, I've got a few places where the boards are squeaking. They happen to be in the spots where I had to use the most 30#. Evidently I didn't get things as flat as I should have.

So now that the floor is down, is there anything I can do? Since the basement is unfinished, I can get to the underside of the plywood.

Is it possible to drill a small hole directly underneath my problem areas and inject something (if so, what should I use?) to remove the low/hollow spot?

Are there other options I'm not thinking of?

Thanks

Ya, an 1-1/8 to 1-1/4" screw, straight up from underneath, as someone stands on top.

Thanks Floorguy.

I hadn't thought about pulling the boards down. I was stuck in thinking that I'd need to fill the void underneath them so they couldn't move.

I'll pick-up some screws on the way home from work.

Use don't sink the heads into the subfloor, or it might go too far and poke out the flooring surface!!!!!!!!!!!!

If you find your sinking them, use 1" screws and sink them a little. ¾ & ¾ gives you 1½ to play with.

Hopefully the noise is not in the sub-floor......

Placing screws in the sub-floor joints in the area of the noise, may help as well.

It is definitely not from the subfloor. I put extra screws in all the joists before I started puttin the wood down.

Plus in a couple of the spots you can see and feel the board move when you apply weight on it.