I recently just installed engineered wood click-lock flooring (floating) over plywood subfloor on our second floor and I noticed some hollow or bounce spots near the entry of the room. The subfloor is plywood and it has a layer of foam underlayment on top and then the flooring. Question: to fix this problem, can I just nail some high spots down to the plywood? I really want to avoid redoing the whole room if possible. What are some other options that I have? The subfloor is not perfectly leveled but it is pretty leveled (I sanded them).
yes you can and that's about all you can do. make sure you use finish nails, I use ringshanks, (paneling nails) and drive them in between the joints to hide them. p.s. you don't really have options now. leveling is top priority, now that's too late, however, they all have some high spots, I don't install them anymore, I hate them.
I once considered a liquid 'injected' fluid that hardens, but abandoned that in favor of pushing the sub-floor up from the basement, bracing the plywood between 2 floor joists. (I never pursued the 'hardening fluid' products.) Injection may require drilling several holes into the flooring to get even distribution of the material, but matching plugs might be available to cover those. Good luck.
At this point there is nothing you can do that will be satisfactory in the long term. Laminate flooring MUST be installed over a sub floor that has very little deviation from flat. the problem here is improper installation. I once remedied a dip in a sub floor by spreading down a filler before installation. After the fact it's simply too late.
sanding the plywood would not make it level, and do not nail into the floating floor this will defeat the floating system and may cause other problems down the road they are floating to allow for expansion and contraction with seasonal changes and nailing a few spots could cause unsightly gaps or even splitting of the material later on and most likely void any warranty since thats not the recommended or proper procedure if there was a fairly large dip in the subfloor this should have been leveled before the install of the finish flooring, some bounce is to be expected from a floor on top of foam underlayment though if its excessive the flooring would need to be removed and low spots in the subfloor filled in with a leveling compound
